Help me please with Spanish

How many brother does francisco have in cajas de carton

Okay so i'm taking an online spanish course (penn foster), and in the study guide, you have to create a bunch of sentences with words you've learned so far. translating, reading, and those kinds of things are fairly easy, but when it comes to making my own sentences, my brain just kinda waltz's away. anyone got any tips?

Which form is the correct form? the clock is on the wall. el reloj estás en la pared. el reloj estuvo en la pared. el reloj es en la pared. el reloj está en la pared.