fix typos (#4938)

beta/src/pages/learn/removing-effect-dependencies.md

@@ -354,7 +354,7 @@ There's always a better solution than ignoring the linter! To fix this code, you
 
 </DeepDive>
 
-## Removing unnecesary dependencies {/*removing-unnecesary-dependencies*/}
+## Removing unnecessary dependencies {/*removing-unnecessary-dependencies*/}
 
 Every time you adjust the Effect's dependencies to reflect the code, look at the dependency list. Does it make sense for the Effect to re-run when any of these dependencies change? Sometimes, the answer is "no":
 
@@ -388,7 +388,7 @@ function Form() {
 }
 ```
 
-Later, you want to style the notification message according to the current theme, so you read the current theme. Since `theme` is declared in the component body, it is a reactive value, and you must declare it as a depedency:
+Later, you want to style the notification message according to the current theme, so you read the current theme. Since `theme` is declared in the component body, it is a reactive value, and you must declare it as a dependency:
 
 ```js {3,9,11}
 function Form() {

beta/src/pages/learn/separating-events-from-effects.md

@@ -210,7 +210,7 @@ Now let's return to these lines:
     // ...
 ```
 
-From the user's prespective, **a change to the `roomId` *does* mean that they want to connect to a different room.** In other words, the logic for connecting to the room should be reactive. You *want* these lines of code to "keep up" with the <CodeStep step={2}>reactive value</CodeStep>, and to run again if that value is different. That's why you put this logic inside an Effect:
+From the user's perspective, **a change to the `roomId` *does* mean that they want to connect to a different room.** In other words, the logic for connecting to the room should be reactive. You *want* these lines of code to "keep up" with the <CodeStep step={2}>reactive value</CodeStep>, and to run again if that value is different. That's why you put this logic inside an Effect:
 
 ```js {2-3}
   useEffect(() => {
@@ -805,7 +805,7 @@ body {
 </Sandpack>
 
 
-The problem with the this code is in suppressing the dependency linter. If you remove the suppression, you'll see that this Effect should depend on the `handleMove` function. This makes sense: `handleMove` is declared inside the component body, which makes it a reactive value. Every reactive value must be specified as a depedency, or it can potentially get stale over time!
+The problem with the this code is in suppressing the dependency linter. If you remove the suppression, you'll see that this Effect should depend on the `handleMove` function. This makes sense: `handleMove` is declared inside the component body, which makes it a reactive value. Every reactive value must be specified as a dependency, or it can potentially get stale over time!
 
 The author of the original code has "lied" to React by saying that the Effect does not depend (`[]`) on any reactive values. This is why React did not re-synchronize the Effect after `canMove` has changed (and `handleMove` with it). Because React did not re-synchronize the Effect, the `handleMove` attached as a listener is the `handleMove` function created during the initial render. During the initial render, `canMove` was `true`, which is why `handleMove` from the initial render will forever see that value.