Learn English – When should I use “caution” instead of “warning” and vice versa

Silence is the absence of sound. It's an absolute adjective, so people don't usually say something is very silent or silenter unless they're playing with words. If something makes no noise at all, it's silent.

Quiet means something is not very loud. It's not an absolute adjective, so you can say something is quieter than something else. If you're comparing several cars, you can say the one which makes the least noise is the quietest.

How do you decide which word to use?

• Use silent if there is no sound.

• Use quiet if there's sound, but it's not very loud.

In the first part, I would say:

Glasses suit you.

though it would be more natural to say:

Glasses look good on you.

Glasses should be treated as a mass noun, since you are not pointing out a specific kind. So no article is used. And suit is better than fit, since fit has more to do with size.

In the second part, I would say:

I think you should go for the blue one. It suits you because your eyes are blue too. So they match.

or simpler:

I think you should go for the blue one. It suits you because they match your blue eyes.