Student or Learner
The population of the world is increasing very fast.
--- how about "increases very fast" Do I have to use the progressive tense "is increasing"?
I'm not a teacher. But I would like a commnet on your question.
I guess both case is grammatically correct. It may depends on what would you like to focus on.
"is increasing" focus on the phenomena or situation, whereas "increases" would be a fact(?), since it makes statement.
sorry I confuse myself.