✏ Fix grammar and add helpful links to dependencies in `docs/en/docs/async.md` (#5432)

docs/en/docs/async.md

@@ -403,17 +403,17 @@ All that is what powers FastAPI (through Starlette) and what makes it have such
 
 When you declare a *path operation function* with normal `def` instead of `async def`, it is run in an external threadpool that is then awaited, instead of being called directly (as it would block the server).
 
-If you are coming from another async framework that does not work in the way described above and you are used to define trivial compute-only *path operation functions* with plain `def` for a tiny performance gain (about 100 nanoseconds), please note that in **FastAPI** the effect would be quite opposite. In these cases, it's better to use `async def` unless your *path operation functions* use code that performs blocking <abbr title="Input/Output: disk reading or writing, network communications.">I/O</abbr>.
+If you are coming from another async framework that does not work in the way described above and you are used to defining trivial compute-only *path operation functions* with plain `def` for a tiny performance gain (about 100 nanoseconds), please note that in **FastAPI** the effect would be quite opposite. In these cases, it's better to use `async def` unless your *path operation functions* use code that performs blocking <abbr title="Input/Output: disk reading or writing, network communications.">I/O</abbr>.
 
 Still, in both situations, chances are that **FastAPI** will [still be faster](/#performance){.internal-link target=_blank} than (or at least comparable to) your previous framework.
 
 ### Dependencies
 
-The same applies for dependencies. If a dependency is a standard `def` function instead of `async def`, it is run in the external threadpool.
+The same applies for [dependencies](/tutorial/dependencies/index.md){.internal-link target=_blank}. If a dependency is a standard `def` function instead of `async def`, it is run in the external threadpool.
 
 ### Sub-dependencies
 
-You can have multiple dependencies and sub-dependencies requiring each other (as parameters of the function definitions), some of them might be created with `async def` and some with normal `def`. It would still work, and the ones created with normal `def` would be called on an external thread (from the threadpool) instead of being "awaited".
+You can have multiple dependencies and [sub-dependencies](/tutorial/dependencies/sub-dependencies.md){.internal-link target=_blank} requiring each other (as parameters of the function definitions), some of them might be created with `async def` and some with normal `def`. It would still work, and the ones created with normal `def` would be called on an external thread (from the threadpool) instead of being "awaited".
 
 ### Other utility functions