I go to the store.
I went to the store.
I will have gone to the store.

I write the book.
I wrote the book.
I will have written the book.

They spend a lot of money.
They spent a lot of money.
They will have spent a lot of money.

They begin the book.
They began the book.
They will have begun the book.

I sing.
I sang.
I will have sung.

I see.
I saw.
I will have seen.

I watch.
I watched.
I will have watched.

I learn.
I learned.
I will have learned.

I eat.
I ate.
I will have eaten.

espero que te sirva. DE NADA