minor grammar changes in Readme.md

README.md

@@ -21,17 +21,17 @@ Pull the image from the Docker repository.
 
 ## Build
 
-For example, if you need to install [Extra Packages](https://pythonhosted.org/airflow/installation.html#extra-package), edit the Dockerfile and than build-it.
+For example, if you need to install [Extra Packages](https://pythonhosted.org/airflow/installation.html#extra-package), edit the Dockerfile and then build it.
 
         docker build --rm -t puckel/docker-airflow .
 
 ## Usage
 
-By default, docker-airflow run Airflow with **SequentialExecutor** :
+By default, docker-airflow runs Airflow with **SequentialExecutor** :
 
         docker run -d -p 8080:8080 puckel/docker-airflow
 
-If you want to run other executor, you've to use the docker-compose.yml files provided in this repository.
+If you want to run another executor, use the other docker-compose.yml files provided in this repository.
 
 For **LocalExecutor** :