"Eu terei olhado para você."

Translation: I will have looked at you.

[Lingodingle]

How does one know that "para" is going to be "at" or "to", and not "for" in this sentence?

[Paulenrique]

Olhar para = look at.

[Armwood]

many times "para" is missing in the portuguese sentences, hm? is there any rule when it must be used and when not?