In English grammar, verbs change in form to tell the time period, or tense. You use different verbs to indicate whether an action has already happened, is currently happening, will happen in the future, and several different variations. Remember these tenses:
Present: happening at the current time (I talk, he talks, they talk)
Present progressive: in the process of happening (I am talking, he is talking, they are talking)
Past: happened before now (I talked, he talked, they talked)
Past progressive: happened over a period of time before now (I was talking, he was talking, they were talking)
Future: will happen after the present time (I will talk, he will talk, they will talk)
Future progressive: will happen over a period of time, after the present time (I will be talking, he will be talking, they will be talking)
Present perfect: started in the past and continues in the present (I have talked, he has talked, they have talked)
Past perfect: happened in the past before another event in the past (I had talked, he had talked, they had talked)
Future perfect: will happen in the future before a deadline (I will have talked, he will have talked, they will have talked)