How to speak English RIGHTLY

In America,people often speak English.We all study English.But there's still a problem.How to speak English rightly,maybe it looks difficult for us.But we have to face to that.Because English is important for the world.And we also study it.Here is the way how to speak English rightly I think. Time

When you talk to someone,if he or she is anEnglish speaking person,I think you need to talk to him or her with the time. For example

You say I went swimming. You say I went swimming yesterday. So what's the different between A and B?Think about it. What do you think of that? By the way if this passage has some mistakes,please tell me that.Thanks so much.