diff --git a/.gitignore b/.gitignore
index a93fffc04..651103706 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,6 @@ build/
 
 # truffle
 .node-xmlhttprequest-*
+
+# IntelliJ IDE
+.idea
diff --git a/contracts/crowdsale/Crowdsale.sol b/contracts/crowdsale/Crowdsale.sol
index be0af7060..6b1c0a642 100644
--- a/contracts/crowdsale/Crowdsale.sol
+++ b/contracts/crowdsale/Crowdsale.sol
@@ -11,8 +11,8 @@ import "../utils/ReentrancyGuard.sol";
  * allowing investors to purchase tokens with ether. This contract implements
  * such functionality in its most fundamental form and can be extended to provide additional
  * functionality and/or custom behavior.
- * The external interface represents the basic interface for purchasing tokens, and conform
- * the base architecture for crowdsales. They are *not* intended to be modified / overridden.
+ * The external interface represents the basic interface for purchasing tokens, and conforms
+ * the base architecture for crowdsales. It is *not* intended to be modified / overridden.
  * The internal interface conforms the extensible and modifiable surface of crowdsales. Override
  * the methods to add functionality. Consider using 'super' where appropriate to concatenate
  * behavior.
@@ -65,7 +65,7 @@ contract Crowdsale is ReentrancyGuard {
 
     /**
      * @dev fallback function ***DO NOT OVERRIDE***
-     * Note that other contracts will transfer fund with a base gas stipend
+     * Note that other contracts will transfer funds with a base gas stipend
      * of 2300, which is not enough to call buyTokens. Consider calling
      * buyTokens directly when purchasing tokens from a contract.
      */
diff --git a/contracts/crowdsale/distribution/FinalizableCrowdsale.sol b/contracts/crowdsale/distribution/FinalizableCrowdsale.sol
index 72249dbbb..9058f70ad 100644
--- a/contracts/crowdsale/distribution/FinalizableCrowdsale.sol
+++ b/contracts/crowdsale/distribution/FinalizableCrowdsale.sol
@@ -5,7 +5,7 @@ import "../validation/TimedCrowdsale.sol";
 
 /**
  * @title FinalizableCrowdsale
- * @dev Extension of Crowdsale with a one-off finalization action, where one
+ * @dev Extension of TimedCrowdsale with a one-off finalization action, where one
  * can do extra work after finishing.
  */
 contract FinalizableCrowdsale is TimedCrowdsale {
diff --git a/contracts/crowdsale/distribution/RefundableCrowdsale.sol b/contracts/crowdsale/distribution/RefundableCrowdsale.sol
index 637bc24fb..21e736fde 100644
--- a/contracts/crowdsale/distribution/RefundableCrowdsale.sol
+++ b/contracts/crowdsale/distribution/RefundableCrowdsale.sol
@@ -6,8 +6,8 @@ import "../../payment/escrow/RefundEscrow.sol";
 
 /**
  * @title RefundableCrowdsale
- * @dev Extension of Crowdsale contract that adds a funding goal, and the possibility of users getting a refund
- * if goal is not met.
+ * @dev Extension of FinalizableCrowdsale contract that adds a funding goal, and the possibility of users
+ * getting a refund if goal is not met.
  *
  * Deprecated, use RefundablePostDeliveryCrowdsale instead. Note that if you allow tokens to be traded before the goal
  * is met, then an attack is possible in which the attacker purchases tokens from the crowdsale and when they sees that
diff --git a/contracts/crowdsale/price/IncreasingPriceCrowdsale.sol b/contracts/crowdsale/price/IncreasingPriceCrowdsale.sol
index 647b532fc..446b41d2e 100644
--- a/contracts/crowdsale/price/IncreasingPriceCrowdsale.sol
+++ b/contracts/crowdsale/price/IncreasingPriceCrowdsale.sol
@@ -28,7 +28,7 @@ contract IncreasingPriceCrowdsale is TimedCrowdsale {
     }
 
     /**
-     * The base rate function is overridden to revert, since this crowdsale doens't use it, and
+     * The base rate function is overridden to revert, since this crowdsale doesn't use it, and
      * all calls to it are a mistake.
      */
     function rate() public view returns (uint256) {
diff --git a/contracts/drafts/Counters.sol b/contracts/drafts/Counters.sol
index 7a68039cc..5af417f18 100644
--- a/contracts/drafts/Counters.sol
+++ b/contracts/drafts/Counters.sol
@@ -8,7 +8,7 @@ import "../math/SafeMath.sol";
  * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
  * of elements in a mapping, issuing ERC721 ids, or counting request ids
  *
- * Include with `using Counter for Counter.Counter;`
+ * Include with `using Counters for Counters.Counter;`
  * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath
  * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
  * directly accessed.
diff --git a/contracts/drafts/ERC20Migrator.sol b/contracts/drafts/ERC20Migrator.sol
index 6553b3d99..3a311383a 100644
--- a/contracts/drafts/ERC20Migrator.sol
+++ b/contracts/drafts/ERC20Migrator.sol
@@ -17,7 +17,7 @@ import "../math/Math.sol";
  * OpenZeppelin's ERC20Mintable, but the only functions that are needed are
  * `isMinter(address)` and `mint(address, amount)`. The migrator will check
  * that it is a minter for the token.
- * The balance from the legacy token will be transfered to the migrator, as it
+ * The balance from the legacy token will be transferred to the migrator, as it
  * is migrated, and remain there forever.
  * Although this contract can be used in many different scenarios, the main
  * motivation was to provide a way to migrate ERC20 tokens into an upgradeable
diff --git a/contracts/drafts/SignatureBouncer.sol b/contracts/drafts/SignatureBouncer.sol
index 89f1f17ae..1fee25764 100644
--- a/contracts/drafts/SignatureBouncer.sol
+++ b/contracts/drafts/SignatureBouncer.sol
@@ -29,7 +29,7 @@ import "../cryptography/ECDSA.sol";
  * @notice A method that uses the `onlyValidSignatureAndData` modifier must make
  * the _signature parameter the "last" parameter. You cannot sign a message that
  * has its own signature in it so the last 128 bytes of msg.data (which
- * represents the length of the _signature data and the _signaature data itself)
+ * represents the length of the _signature data and the _signature data itself)
  * is ignored when validating. Also non fixed sized parameters make constructing
  * the data in the signature much more complex.
  * See https://ethereum.stackexchange.com/a/50616 for more details.
@@ -56,7 +56,7 @@ contract SignatureBouncer is SignerRole {
     }
 
     /**
-     * @dev requires that a valid signature with a specifed method of a signer was provided
+     * @dev requires that a valid signature with a specified method of a signer was provided
      */
     modifier onlyValidSignatureAndMethod(bytes memory signature) {
         require(_isValidSignatureAndMethod(msg.sender, signature));
@@ -64,7 +64,7 @@ contract SignatureBouncer is SignerRole {
     }
 
     /**
-     * @dev requires that a valid signature with a specifed method and params of a signer was provided
+     * @dev requires that a valid signature with a specified method and params of a signer was provided
      */
     modifier onlyValidSignatureAndData(bytes memory signature) {
         require(_isValidSignatureAndData(msg.sender, signature));
@@ -72,7 +72,7 @@ contract SignatureBouncer is SignerRole {
     }
 
     /**
-     * @dev is the signature of `this + sender` from a signer?
+     * @dev is the signature of `this + account` from a signer?
      * @return bool
      */
     function _isValidSignature(address account, bytes memory signature) internal view returns (bool) {
@@ -80,7 +80,7 @@ contract SignatureBouncer is SignerRole {
     }
 
     /**
-     * @dev is the signature of `this + sender + methodId` from a signer?
+     * @dev is the signature of `this + account + methodId` from a signer?
      * @return bool
      */
     function _isValidSignatureAndMethod(address account, bytes memory signature) internal view returns (bool) {
@@ -92,7 +92,7 @@ contract SignatureBouncer is SignerRole {
     }
 
     /**
-     * @dev is the signature of `this + sender + methodId + params(s)` from a signer?
+     * @dev is the signature of `this + account + methodId + params(s)` from a signer?
      * @notice the signature parameter of the method being validated must be the "last" parameter
      * @return bool
      */
diff --git a/contracts/drafts/TokenVesting.sol b/contracts/drafts/TokenVesting.sol
index 7bd4e02cf..636f94bf1 100644
--- a/contracts/drafts/TokenVesting.sol
+++ b/contracts/drafts/TokenVesting.sol
@@ -12,7 +12,7 @@ import "../math/SafeMath.sol";
  */
 contract TokenVesting is Ownable {
     // The vesting schedule is time-based (i.e. using block timestamps as opposed to e.g. block numbers), and is
-    // therefore sensitive to timestamp manipulation (which is something miners can do, to a certain degree).Therefore,
+    // therefore sensitive to timestamp manipulation (which is something miners can do, to a certain degree). Therefore,
     // it is recommended to avoid using short time durations (less than a minute). Typical vesting schemes, with a
     // cliff period of a year and a duration of four years, are safe to use.
     // solhint-disable not-rely-on-time
diff --git a/contracts/ownership/Ownable.sol b/contracts/ownership/Ownable.sol
index 4acc0cbab..9780c07fd 100644
--- a/contracts/ownership/Ownable.sol
+++ b/contracts/ownership/Ownable.sol
@@ -43,9 +43,10 @@ contract Ownable {
 
     /**
      * @dev Allows the current owner to relinquish control of the contract.
-     * @notice Renouncing to ownership will leave the contract without an owner.
      * It will not be possible to call the functions with the `onlyOwner`
      * modifier anymore.
+     * @notice Renouncing ownership will leave the contract without an owner,
+     * thereby removing any functionality that is only available to the owner.
      */
     function renounceOwnership() public onlyOwner {
         emit OwnershipTransferred(_owner, address(0));
diff --git a/contracts/payment/escrow/RefundEscrow.sol b/contracts/payment/escrow/RefundEscrow.sol
index 22c08075f..8c3904779 100644
--- a/contracts/payment/escrow/RefundEscrow.sol
+++ b/contracts/payment/escrow/RefundEscrow.sol
@@ -83,7 +83,7 @@ contract RefundEscrow is ConditionalEscrow {
     }
 
     /**
-     * @dev Returns whether refundees can withdraw their deposits (be refunded). The overriden function receives a
+     * @dev Returns whether refundees can withdraw their deposits (be refunded). The overridden function receives a
      * 'payee' argument, but we ignore it here since the condition is global, not per-payee.
      */
     function withdrawalAllowed(address) public view returns (bool) {
diff --git a/contracts/token/ERC20/ERC20.sol b/contracts/token/ERC20/ERC20.sol
index 55277a8df..1d697525e 100644
--- a/contracts/token/ERC20/ERC20.sol
+++ b/contracts/token/ERC20/ERC20.sol
@@ -51,7 +51,7 @@ contract ERC20 is IERC20 {
     }
 
     /**
-     * @dev Transfer token for a specified address
+     * @dev Transfer token to a specified address
      * @param to The address to transfer to.
      * @param value The amount to be transferred.
      */
@@ -90,7 +90,7 @@ contract ERC20 is IERC20 {
 
     /**
      * @dev Increase the amount of tokens that an owner allowed to a spender.
-     * approve should be called when allowed_[_spender] == 0. To increment
+     * approve should be called when _allowed[msg.sender][spender] == 0. To increment
      * allowed value is better to use this function to avoid 2 calls (and wait until
      * the first transaction is mined)
      * From MonolithDAO Token.sol
@@ -105,7 +105,7 @@ contract ERC20 is IERC20 {
 
     /**
      * @dev Decrease the amount of tokens that an owner allowed to a spender.
-     * approve should be called when allowed_[_spender] == 0. To decrement
+     * approve should be called when _allowed[msg.sender][spender] == 0. To decrement
      * allowed value is better to use this function to avoid 2 calls (and wait until
      * the first transaction is mined)
      * From MonolithDAO Token.sol
diff --git a/contracts/token/ERC721/ERC721Enumerable.sol b/contracts/token/ERC721/ERC721Enumerable.sol
index 773437791..0b5fd9c09 100644
--- a/contracts/token/ERC721/ERC721Enumerable.sol
+++ b/contracts/token/ERC721/ERC721Enumerable.sol
@@ -33,7 +33,7 @@ contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
      * @dev Constructor function
      */
     constructor () public {
-        // register the supported interface to conform to ERC721 via ERC165
+        // register the supported interface to conform to ERC721Enumerable via ERC165
         _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
     }
 
@@ -167,8 +167,8 @@ contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
         // This also deletes the contents at the last position of the array
         _ownedTokens[from].length--;
 
-        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occcupied by
-        // lasTokenId, or just over the end of the array if the token was the last one).
+        // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by
+        // lastTokenId, or just over the end of the array if the token was the last one).
     }
 
     /**
diff --git a/contracts/utils/Arrays.sol b/contracts/utils/Arrays.sol
index 1957802b1..90f9e88d1 100644
--- a/contracts/utils/Arrays.sol
+++ b/contracts/utils/Arrays.sol
@@ -9,8 +9,8 @@ import "../math/Math.sol";
  */
 library Arrays {
     /**
-     * @dev Upper bound search function which is kind of binary search algoritm. It searches sorted
-     * array to find index of the element value. If element is found then returns it's index otherwise
+     * @dev Upper bound search function which is kind of binary search algorithm. It searches sorted
+     * array to find index of the element value. If element is found then returns its index otherwise
      * it returns index of first element which is greater than searched value. If searched element is
      * bigger than any array element function then returns first index after last element (i.e. all
      * values inside the array are smaller than the target). Complexity O(log n).
diff --git a/test/crowdsale/AllowanceCrowdsale.test.js b/test/crowdsale/AllowanceCrowdsale.test.js
index d6bec5b78..c05badb34 100644
--- a/test/crowdsale/AllowanceCrowdsale.test.js
+++ b/test/crowdsale/AllowanceCrowdsale.test.js
@@ -54,7 +54,7 @@ contract('AllowanceCrowdsale', function ([_, investor, wallet, purchaser, tokenW
   });
 
   describe('check remaining allowance', function () {
-    it('should report correct allowace left', async function () {
+    it('should report correct allowance left', async function () {
       const remainingAllowance = tokenAllowance.sub(expectedTokenAmount);
       await this.crowdsale.buyTokens(investor, { value: value, from: purchaser });
       (await this.crowdsale.remainingTokens()).should.be.bignumber.equal(remainingAllowance);
@@ -72,7 +72,7 @@ contract('AllowanceCrowdsale', function ([_, investor, wallet, purchaser, tokenW
     });
   });
 
-  describe('when token wallet is different from token address', function () {
+  describe('when token wallet is the zero address', function () {
     it('creation reverts', async function () {
       this.token = await SimpleToken.new({ from: tokenWallet });
       await shouldFail.reverting(AllowanceCrowdsaleImpl.new(rate, wallet, this.token.address, ZERO_ADDRESS));
diff --git a/test/crowdsale/IncreasingPriceCrowdsale.test.js b/test/crowdsale/IncreasingPriceCrowdsale.test.js
index 376c1ccfb..387e3ff6f 100644
--- a/test/crowdsale/IncreasingPriceCrowdsale.test.js
+++ b/test/crowdsale/IncreasingPriceCrowdsale.test.js
@@ -31,7 +31,7 @@ contract('IncreasingPriceCrowdsale', function ([_, investor, wallet, purchaser])
       ));
     });
 
-    it('reverts with a final equal to the initial rate', async function () {
+    it('reverts with a final rate equal to the initial rate', async function () {
       await shouldFail.reverting(IncreasingPriceCrowdsaleImpl.new(
         this.startTime, this.closingTime, wallet, this.token.address, initialRate, initialRate
       ));
diff --git a/test/drafts/SignedSafeMath.test.js b/test/drafts/SignedSafeMath.test.js
index 59157a1e3..b40adf6e6 100644
--- a/test/drafts/SignedSafeMath.test.js
+++ b/test/drafts/SignedSafeMath.test.js
@@ -19,7 +19,7 @@ contract('SignedSafeMath', function () {
   }
 
   describe('add', function () {
-    it('adds correctly if it does not overflow and the result is positve', async function () {
+    it('adds correctly if it does not overflow and the result is positive', async function () {
       const a = new BN('1234');
       const b = new BN('5678');
 
diff --git a/test/lifecycle/Pausable.test.js b/test/lifecycle/Pausable.test.js
index 337adcfc7..fc9371b4b 100644
--- a/test/lifecycle/Pausable.test.js
+++ b/test/lifecycle/Pausable.test.js
@@ -17,7 +17,7 @@ contract('Pausable', function ([_, pauser, otherPauser, anyone, ...otherAccounts
     shouldBehaveLikePublicRole(pauser, otherPauser, otherAccounts, 'pauser');
   });
 
-  context('when unapused', function () {
+  context('when unpaused', function () {
     beforeEach(async function () {
       (await this.pausable.paused()).should.equal(false);
     });
diff --git a/test/ownership/Ownable.behavior.js b/test/ownership/Ownable.behavior.js
index 5e90222f2..6cfd61d8a 100644
--- a/test/ownership/Ownable.behavior.js
+++ b/test/ownership/Ownable.behavior.js
@@ -16,7 +16,7 @@ function shouldBehaveLikeOwnable (owner, [anyone]) {
       (await this.ownable.isOwner({ from: anyone })).should.be.equal(true);
     });
 
-    it('should prevent non-owners from transfering', async function () {
+    it('should prevent non-owners from transferring', async function () {
       await shouldFail.reverting(this.ownable.transferOwnership(anyone, { from: anyone }));
     });
 
diff --git a/test/ownership/Secondary.test.js b/test/ownership/Secondary.test.js
index e46784a15..8e55dc12e 100644
--- a/test/ownership/Secondary.test.js
+++ b/test/ownership/Secondary.test.js
@@ -29,7 +29,7 @@ contract('Secondary', function ([_, primary, newPrimary, anyone]) {
       (await this.secondary.primary()).should.equal(newPrimary);
     });
 
-    it('reverts when transfering to the null address', async function () {
+    it('reverts when transferring to the null address', async function () {
       await shouldFail.reverting(this.secondary.transferPrimary(ZERO_ADDRESS, { from: primary }));
     });
 
diff --git a/test/payment/PaymentSplitter.test.js b/test/payment/PaymentSplitter.test.js
index 4eeaff329..b9f097e76 100644
--- a/test/payment/PaymentSplitter.test.js
+++ b/test/payment/PaymentSplitter.test.js
@@ -84,19 +84,19 @@ contract('PaymentSplitter', function ([_, owner, payee1, payee2, payee3, nonpaye
       const initAmount1 = await balance.current(payee1);
       const { logs: logs1 } = await this.contract.release(payee1, { gasPrice: 0 });
       const profit1 = (await balance.current(payee1)).sub(initAmount1);
-      profit1.should.be.bignumber.equal(ether('0.20', 'ether'));
+      profit1.should.be.bignumber.equal(ether('0.20'));
       expectEvent.inLogs(logs1, 'PaymentReleased', { to: payee1, amount: profit1 });
 
       const initAmount2 = await balance.current(payee2);
       const { logs: logs2 } = await this.contract.release(payee2, { gasPrice: 0 });
       const profit2 = (await balance.current(payee2)).sub(initAmount2);
-      profit2.should.be.bignumber.equal(ether('0.10', 'ether'));
+      profit2.should.be.bignumber.equal(ether('0.10'));
       expectEvent.inLogs(logs2, 'PaymentReleased', { to: payee2, amount: profit2 });
 
       const initAmount3 = await balance.current(payee3);
       const { logs: logs3 } = await this.contract.release(payee3, { gasPrice: 0 });
       const profit3 = (await balance.current(payee3)).sub(initAmount3);
-      profit3.should.be.bignumber.equal(ether('0.70', 'ether'));
+      profit3.should.be.bignumber.equal(ether('0.70'));
       expectEvent.inLogs(logs3, 'PaymentReleased', { to: payee3, amount: profit3 });
 
       // end balance should be zero
diff --git a/test/token/ERC721/ERC721PausedToken.behavior.js b/test/token/ERC721/ERC721PausedToken.behavior.js
index 59ed060c1..a116c8394 100644
--- a/test/token/ERC721/ERC721PausedToken.behavior.js
+++ b/test/token/ERC721/ERC721PausedToken.behavior.js
@@ -55,7 +55,7 @@ function shouldBehaveLikeERC721PausedToken (owner, [recipient, operator]) {
     });
 
     describe('exists', function () {
-      it('should return token existance', async function () {
+      it('should return token existence', async function () {
         (await this.token.exists(firstTokenId)).should.equal(true);
       });
     });