docs: fix grammar (#4949)

* docs: fix grammar

* Update strict-mode.md

Co-authored-by: dan <dan.abramov@gmail.com>

content/docs/strict-mode.md

@@ -134,7 +134,7 @@ Read the [new context API documentation](/docs/context.html) to help migrate to
 
 ### Ensuring reusable state {#ensuring-reusable-state}
 
-In the future, we’d like to add a feature that allows React to add and remove sections of the UI while preserving state. For example, when a user tabs away from a screen and back, React should be able to immediately show the previous screen. To do this, React support remounting trees using the same component state used before unmounting.
+In the future, we’d like to add a feature that allows React to add and remove sections of the UI while preserving state. For example, when a user tabs away from a screen and back, React should be able to immediately show the previous screen. To do this, React will support remounting trees using the same component state used before unmounting.
 
 This feature will give React better performance out-of-the-box, but requires components to be resilient to effects being mounted and destroyed multiple times. Most effects will work without any changes, but some effects do not properly clean up subscriptions in the destroy callback, or implicitly assume they are only mounted or destroyed once.