diff --git a/Part 2 - Sequence Basics/4. Aggregation.md b/Part 2 - Sequence Basics/4. Aggregation.md
index 68459d1..7687cfc 100644
--- a/Part 2 - Sequence Basics/4. Aggregation.md	
+++ b/Part 2 - Sequence Basics/4. Aggregation.md	
@@ -543,7 +543,7 @@ Nested observables may be confusing at first, but they are a powerful construct
  
 ### nest
 
-When dealing with nested observables, the `nest` operator becomes useful. It allows you to turn a non-nested observable into a nested observable. `nest` takes a source observable and returns an observable that will be the source observable and then terminate.
+When dealing with nested observables, the `nest` operator becomes useful. It allows you to turn a non-nested observable into a nested one. `nest` takes a source observable and returns an observable that will emit the source observable and then terminate.
 
 ![](https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/nest.png)
 
@@ -559,7 +559,7 @@ Observable.range(0, 3)
 2
 ```
 
-Nesting observables to consume them doesn't make much sense. Towards the end of the pipeline, you'd rather flatten and simply your observables, rather than nest them. Nesting is useful when you need to make a non-nested observable be of the same type as a nested observable that you have from elsewhere. Once they are of the same type, you can combine them, as we will see in the chapter about [combining sequences](/Part 3 - Taming the sequence/4. Combining sequences.md).
+Nesting observables to consume them doesn't make much sense. Towards the end of the pipeline, you'd rather flatten and simplify your observables, rather than nest them. Nesting is useful when you need to make a non-nested observable be of the same type as a nested observable that you have from elsewhere. Once they are of the same type, you can combine them, as we will see in the chapter about [combining sequences](/Part 3 - Taming the sequence/4. Combining sequences.md).
 
 
 
diff --git a/Part 3 - Taming the sequence/7. Custom operators.md b/Part 3 - Taming the sequence/7. Custom operators.md
index 0f500c1..4fec2a2 100644
--- a/Part 3 - Taming the sequence/7. Custom operators.md	
+++ b/Part 3 - Taming the sequence/7. Custom operators.md	
@@ -378,7 +378,7 @@ source.doOnUnsubscribe(() -> System.out.println("Unsubscribed"))
 Completed
 ```
 
-We here that, despite the fact that we did not unsubscribe, the illegal notifications were filtered out.
+We see that, despite the fact that we did not unsubscribe, the illegal notifications were filtered out.
 
 
 
diff --git a/Part 4 - Concurrency/4. Backpressure.md b/Part 4 - Concurrency/4. Backpressure.md
index 3777e1c..f239ff7 100644
--- a/Part 4 - Concurrency/4. Backpressure.md	
+++ b/Part 4 - Concurrency/4. Backpressure.md	
@@ -147,7 +147,7 @@ The `request(1)` in `onStart` establishes backpressure and informs the observabl
 
 ### doOnRequested
 
-Back we where discussing the `doOn_` operators for [side effects](/Part%203%20-%20Taming%20the%20sequence/1.%20Side%20effects.md#do), we left out `doOnRequested`. 
+Back when we were discussing the `doOn_` operators for [side effects](/Part%203%20-%20Taming%20the%20sequence/1.%20Side%20effects.md#do), we left out `doOnRequested`. 
 ```java
 public final Observable<T> doOnRequest(Action1<java.lang.Long> onRequest)
 ```
@@ -348,7 +348,7 @@ Observable.interval(1, TimeUnit.MILLISECONDS)
 ...
 ```
 
-What we see here is that the first 128 items where consumed normally, but then we jumped forward. The items inbetween were dropped by `onBackPressureDrop`. Even though we did not request it, the first 128 items where still buffered, since `observeOn` uses a small buffer between switching threads.
+What we see here is that the first 128 items where consumed normally, but then we jumped forward. The items inbetween were dropped by `onBackPressureDrop`. Even though we did not request it, the first 128 items were still buffered, since `observeOn` uses a small buffer between switching threads.
 
 
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