✏ Fix typos in docs for dependencies (#1675)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

docs/en/docs/tutorial/dependencies/classes-as-dependencies.md

@@ -69,7 +69,7 @@ If you pass a "callable" as a dependency in **FastAPI**, it will analyze the par
 
 That also applies to callables with no parameters at all. The same as it would be for *path operation functions* with no parameters.
 
-Then, we can change the dependency "dependable" `common_parameters` from above to the class `CommonQueryParameters`:
+Then, we can change the dependency "dependable" `common_parameters` from above to the class `CommonQueryParams`:
 
 ```Python hl_lines="11 12 13 14 15"
 {!../../../docs_src/dependencies/tutorial002.py!}
@@ -101,15 +101,15 @@ In both cases the data will be converted, validated, documented on the OpenAPI s
 
 Now you can declare your dependency using this class.
 
-And as when **FastAPI** calls that class the value that will be passed as `commons` to your function will be an "instance" of the class, you can declare that parameter `commons` to be of type of the class, `CommonQueryParams`.
-
 ```Python hl_lines="19"
 {!../../../docs_src/dependencies/tutorial002.py!}
 ```
 
+**FastAPI** calls the `CommonQueryParams` class. This creates an "instance" of that class and the instance will be passed as the parameter `commons` to your function.
+
 ## Type annotation vs `Depends`
 
-In the code above, you are declaring `commons` as:
+Notice how we write `CommonQueryParams` twice in the above code:
 
 ```Python
 commons: CommonQueryParams = Depends(CommonQueryParams)
@@ -175,9 +175,9 @@ commons: CommonQueryParams = Depends(CommonQueryParams)
 commons: CommonQueryParams = Depends()
 ```
 
-So, you can declare the dependency as the type of the variable, and use `Depends()` as the "default" value (the value after the `=`) for that function's parameter, without any parameter, instead of having to write the full class *again* inside of `Depends(CommonQueryParams)`.
+You declare the dependency as the type of the parameter, and you use `Depends()` as its "default" value (that after the `=`) for that function's parameter, without any parameter in `Depends()`, instead of having to write the full class *again* inside of `Depends(CommonQueryParams)`.
 
-So, the same example would look like:
+The same example would then look like:
 
 ```Python hl_lines="19"
 {!../../../docs_src/dependencies/tutorial004.py!}
@@ -186,6 +186,6 @@ So, the same example would look like:
 ...and **FastAPI** will know what to do.
 
 !!! tip
-    If all that seems more confusing than helpful, disregard it, you don't *need* it.
-    
+    If that seems more confusing than helpful, disregard it, you don't *need* it.
+
     It is just a shortcut. Because **FastAPI** cares about helping you minimize code repetition.

docs/en/docs/tutorial/dependencies/dependencies-in-path-operation-decorators.md

@@ -25,7 +25,7 @@ These dependencies will be executed/solved the same way normal dependencies. But
 
     Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.
 
-    It might also help avoiding confusion for new developers that see an un-used parameter in your code and could think it's unnecessary.
+    It might also help avoid confusion for new developers that see an unused parameter in your code and could think it's unnecessary.
 
 ## Dependencies errors and return values
 

docs/en/docs/tutorial/dependencies/index.md

@@ -39,7 +39,7 @@ That's it.
 
 **2 lines**.
 
-And it has the same shape and structure that all your *path operation functions*.
+And it has the same shape and structure that all your *path operation functions* have.
 
 You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).
 
@@ -123,10 +123,9 @@ So, the interactive docs will have all the information from these dependencies t
 
 <img src="/img/tutorial/dependencies/image01.png">
 
-
 ## Simple usage
 
-If you look at it, *path operation functions* are declared to be used whenever a *path* and *operation* matches, and then **FastAPI** takes care of calling the function with the correct parameters and use the response.
+If you look at it, *path operation functions* are declared to be used whenever a *path* and *operation* matches, and then **FastAPI** takes care of calling the function with the correct parameters, extracting the data from the request.
 
 Actually, all (or most) of the web frameworks work in this same way.
 

docs/en/docs/tutorial/dependencies/sub-dependencies.md

@@ -31,7 +31,7 @@ Let's focus on the parameters declared:
 * Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
     * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
 * It also declares an optional `last_query` cookie, as a `str`.
-    * Let's imagine that if the user didn't provide any query `q`, we just use the last query used, that we had saved to a cookie before.
+    * If the user didn't provide any query `q`, we use the last query used, which we saved to a cookie before.
 
 ### Use the dependency