Renato,

The examples you gave are fine and likely to be heard in spoken English. However, if you're taking an examination in English (Cambridge Papers, TOEFL, etc.), those same examples will be marked wrong. That's because it is said that in "proper" English you can't use forget if you mention the place where you have left something. You should use left, instead.

ex.: I've forgotten my umbrella at home. (wrong)

      I've left my umbrella at home. (correct)

In spoken English, however, both examples would be "acceptable" and widely used.