Use of Rather, Would Rather, Rather than in English - Basic English Grammar

In this video, Alisha answers 5 questions. - Could you please tell me what "can't you tell?" means? - What is the meaning of "rather." I really can't use it in a sentence. - What's the difference between "important" ,"essential" and "significant"? What is the meaning of "time after time", "year after year" and "day after day"? - Please, tell me what's the difference between "I go" and "I will go"? - Is there the difference between "because" and "cause"? It ssems to me they have a similar meaning, isn't it?