When we speak and write in English, we use abbreviations.
The word because is often written as, or pronounced as: 'cause / cos / coz.
For instance, you might hear:
I take the train to work 'cause it's quicker than the bus.
When people send text messages, they might write:
I went home early cos I wasn't feeling well.
In today's Question and Answer of the Week, Rosie and Helen talk about this abbreviation and a few others!
If you want a question answered too, just send it to questions.chinaelt@bbc.co.uk