HOW WE CAN COMMUNICATE WITH A NON NATIVE SPEAKER

This is true that a native speaker have different accent than a non native speaker so use proper pronunciation      rather than short forms.

Do not interrupt when talking to non native speakers they might lose confidence.

Avoid using running words this may not be understandable to other person.

If ask to repeat lines then first repeat it till the other person get it properly.

Listen to non native speakers patiently.

http://www.wikihow.com/Communicate-with-a-Non-Native-English-Speaker