Apply suggestions from code review

Signed-off-by: Josh Humphries <2035234+jhump@users.noreply.github.com>

docs/testing_clients.md

@@ -201,7 +201,7 @@ ignored (and the headers and/or trailers treated as empty).
 The `ClientCompatRequest` can contain instructions for the client program to cancel the
 RPC before it has completed. Ideally, when the RPC is canceled based on these instructions,
 the rest of the invocation logic should proceed as if it had _not_ been canceled. This way,
-the client program can exercises the client implementation's cancellation handling, and how
+the client program can exercise the client implementation's cancellation handling, and how
 it impacts subsequent operations for the call. This allows the conformance suite to verify
 that asynchronous cancellations are handled correctly by the implementation and result in
 proper notification of the cancellation to the code that is consuming the RPC results.
@@ -253,7 +253,7 @@ construct a result using the payload and any available headers
 ```
 
 _*_ Note: some client APIs will provide a blocking operation for unary RPCs,
-    which doesn't return until the RPC response is recevied. For these cases,
+    which doesn't return until the RPC response is received. For these cases,
     you must arrange for the RPC to be canceled asynchronously after the indicated
     number of milliseconds, and then invoke the blocking operation.