Update using-environment-variables.mdx (#9040)

### Description
Add missing word.

### Testing Instructions
N/A

docs/repo-docs/crafting-your-repository/using-environment-variables.mdx

@@ -30,7 +30,7 @@ There are three important questions when working with environment variables in T
 
 ## Adding environment variables to task hashes
 
-Turborepo needs to be aware your environment variables to account for changes in application behavior. To do this, use the `env` and `globalEnv` keys in your `turbo.json` file.
+Turborepo needs to be aware of your environment variables to account for changes in application behavior. To do this, use the `env` and `globalEnv` keys in your `turbo.json` file.
 
 ```json title="./turbo.json"
 {