Did you know that the word as can be used as three parts of the speech? preposition, conjunction and adverb? Me neither, but that is why we learn something new every day. Let’s dig in.
- It’s not as well made, but it’s twice as expensive. (extent or degree)
- He was never seen as the boss, rather than as a friend. (manner or role)
- As you wish, my lord. (in the same way)
- As I came in, she left. (at the same time)
- As it’s too late, I quit. (because)
- What is your opinion as a parent? (in the role of)
- You are not as tall as me. (basis of comparison in the objective case)
- On this issue they thought as one. (in a manner similar to)
I am not pretending that I understand how are the example sentences in the preposition different from sentences in adverbs or conjunctions. Both Wikitionary and The Free Dictionary agree on that though, so there you have it.