Correct mis-use of "it's"

2-ui/1-document/04-searching-elements-dom/article.md

@@ -55,7 +55,7 @@ Also, there's a global variable named by `id` that references the element:
 ```
 
 ```warn header="Please don't use id-named global variables to access elements"
-This behavior is described [in the specification](http://www.whatwg.org/specs/web-apps/current-work/#dom-window-nameditem), so it's kind of standard. But it is supported mainly for compatibility.
+This behavior is described [in the specification](http://www.whatwg.org/specs/web-apps/current-work/#dom-window-nameditem), so it's a kind of standard. But it is supported mainly for compatibility.
 
 The browser tries to help us by mixing namespaces of JS and DOM. That's fine for simple scripts, inlined into HTML, but generally isn't a good thing. There may be naming conflicts. Also, when one reads JS code and doesn't have HTML in view, it's not obvious where the variable comes from.
 

2-ui/1-document/09-size-and-scroll/article.md

@@ -17,8 +17,8 @@ As a sample element to demonstrate properties we'll use the one given below:
     width: 300px;
     height: 200px;
     border: 25px solid #E8C48F;
-    padding: 20px;              
-    overflow: auto;             
+    padding: 20px;
+    overflow: auto;
   }
 </style>
 ```
@@ -106,7 +106,7 @@ Geometry properties are calculated only for displayed elements.
 
 If an element (or any of its ancestors) has `display:none` or is not in the document, then all geometry properties are zero (or `null` for `offsetParent`).
 
-For example, `offsetParent` is `null`, and `offsetWidth`, `offsetHeight` are `0` when we created an element, but haven't inserted it into the document yet, or it (or it's ancestor) has `display:none`.
+For example, `offsetParent` is `null`, and `offsetWidth`, `offsetHeight` are `0` when we created an element, but haven't inserted it into the document yet, or it (or its ancestor) has `display:none`.
 
 We can use this to check if an element is hidden, like this:
 

2-ui/2-events/05-dispatch-events/article.md

@@ -210,7 +210,7 @@ Please note: the event must have the flag `cancelable: true`, otherwise the call
 
 ## Events-in-events are synchronous
 
-Usually events are processed in a queue. That is: if the browser is processing `onclick` and a new event occurs, e.g. mouse moved, then it's handling is queued up, corresponding `mousemove` handlers will be called after `onclick` processing is finished.
+Usually events are processed in a queue. That is: if the browser is processing `onclick` and a new event occurs, e.g. mouse moved, then its handling is queued up, corresponding `mousemove` handlers will be called after `onclick` processing is finished.
 
 The notable exception is when one event is initiated from within another one, e.g. using `dispatchEvent`. Such events are processed immediately: the new event handlers are called, and then the current event handling is resumed.
 

2-ui/3-event-details/4-mouse-drag-and-drop/article.md

@@ -23,14 +23,14 @@ These are the basics. Later we'll see how to other features, such as highlightin
 Here's the implementation of dragging a ball:
 
 ```js
-ball.onmousedown = function(event) { 
+ball.onmousedown = function(event) {
   // (1) prepare to moving: make absolute and on top by z-index
   ball.style.position = 'absolute';
   ball.style.zIndex = 1000;
 
   // move it out of any current parents directly into body
   // to make it positioned relative to the body
-  document.body.append(ball);  
+  document.body.append(ball);
 
   // centers the ball at (pageX, pageY) coordinates
   function moveAt(pageX, pageY) {
@@ -93,7 +93,7 @@ So we should listen on `document` to catch it.
 
 ## Correct positioning
 
-In the examples above the ball is always moved so, that it's center is under the pointer:
+In the examples above the ball is always moved so that its center is under the pointer:
 
 ```js
 ball.style.left = pageX - ball.offsetWidth / 2 + 'px';

2-ui/4-forms-controls/3-events-change-input/article.md

@@ -85,7 +85,7 @@ So the example above uses `document.getSelection()` to get the selected text. Yo
 
 It's possible to copy/paste not just text, but everything. For instance, we can copy a file in the OS file manager, and paste it.
 
-That's because `clipboardData` implements `DataTransfer` interface, commonly used for drag'n'drop and copy/pasting. It's bit beyond our scope now, but you can find its methods in the [DataTransfer specification](https://html.spec.whatwg.org/multipage/dnd.html#the-datatransfer-interface).
+That's because `clipboardData` implements `DataTransfer` interface, commonly used for drag'n'drop and copy/pasting. It's a bit beyond our scope now, but you can find its methods in the [DataTransfer specification](https://html.spec.whatwg.org/multipage/dnd.html#the-datatransfer-interface).
 
 Also, there's an additional asynchronous API of accessing the clipboard: `navigator.clipboard`. More about it in the specification [Clipboard API and events](https://www.w3.org/TR/clipboard-apis/), [not supported by Firefox](https://caniuse.com/async-clipboard).