Hi, Flávio. "I've" comes from "I have". After "I've" there's usually a past participle (the third form of the verb): I've done (from to do - do / did / done), I've eaten (from to eat - eat / ate / eaten), I've had (from to have - have / had / had). Thus, you can say "I've had a busy day so far" or "I have had a busy day so far", but you can only say "I have two brothers" (we don't say "I've two brothers"). I've had / I have had - Present Simple (it shows an action that started in the past but it's somehow related to the present moment (I've had a busy day so far - the day hasn't finished) I had - Past Simple (it shows an action that started in the past and is now completed (I had a busy day yesterday)

I 've = I have Had is the past tense of have. I have a car = now I had a car = before, in the past I have been = present perfect ( past situation related to present,now ) I had been = past perfect ( a past situation which happened before another situation in the past )

Olá Flávio . Eu acho que você queria perguntar a diferença entre I've. (abreviação de "I have" = presente e I had = perfeito.