What words in the sentence do you make plural?

Question

I have two questions.. Wondering if there is a solid rule to follow as far as making sentences plural in Spanish. I understand how to make words plural but which words or parts of the words to we make plural? Is it just the adjectives, nouns and verbs that you make plural? In this case "bastante" is an adjective but may or may not need to be plural, how do I know when a word must be plural?

Question 1 Cómo son las películas de terror? Son bastantes horribles o Son bastante horribles?

Te gustan más las verduras o las frutas? Me dan iguales or me da igual?

Te gustan los deportes? Sí son algos divertidos o Sí son algo divertidos?

Question 2 Office buildings Is it edificio de oficinas, edificios de oficinas, o edificios de oficina?

How do I know which one is correct, is there a rule here?

Thanks so much!

Answer 1

Perhaps this article will help regarding adjectives of quantity.

Regarding office buildings, the translation would be edificios de oficinas.

Good article K-G.Thanks. Somewhat confusing for new learners here in the Canaries where the natives have the " bad " habit of cutting the "s" at the end of words. Dos sounds like "do" etc. Cheers! - britisk, Apr 1, 2014

Thanks Kiwi-Girl for your input, the article will be a great reference! - Andrea8Colon, Apr 2, 2014