When do I used the preposition "a" plus a pronoun or noun?

Question

I'm going by this lesson.

If "Me agrada su visita" means "I am pleased by your visit." then why do I need "A nosotros" to say "A nosotros nos molesta el ruido" (We are bothered by the noise)

Thanks!

Answer 1

You do not need A nosotros in that sentence. It may have been used for emphasis.

Nos molesta el ruido. is correct.

A nosotros nos molesta el ruido. We are bothered by the noise (even if you aren't).

In English we use tone of voice to show emphasis.