I am the light -noun
You light up my world-verb
I like you-verb
What would you like -noun
This is supposed to be math
Yes. He saw them has a subject (he), a verb (saw), and an object (them), so it is totally a sentence.
The central topic in this scene is clothing. When King Duncan grants Macbeth with thane of Cawdor, Macbeth refers to this title as "borrowed robes" because thane is alive and he doesn't want to wear the old man's clothing. Clothing is a symbolism for rank here representing the status in a community, in this scene in a royal one. Macbeth doesn't want the rank while the holder is still alive.