Someone I work with in an ESL setting is using "It's because..." to begin his sentences and I believe it doesn't sound natural. I am aware that he should be using 'because' to join the sentences but for argument sake I want to know if it is grammatically correct to begin a sentence with "It's because".
I want to become a fireman.
It's because I want to help people who are in need.
I think students should use eletronic dictionaries. It's because they are more convenient.