I doubt (clause)

"I doubt ___" means "I don't think ___":

I doubt I'll be able to make it.

I doubt the weather will be any better tomorrow.

But you can't substitute "I doubt" for "I don't think" in sentences like this one:

I don't think he should do that.

In this sentence, "I think" is used to express your opinion. "I doubt" can only replace "I don't think ___" when it's being used to make a guess.

The phrase "I doubt ___" carries a greater level of disbelief than "I don't think ___". In other words, use "I doubt ___" for things that you really don't think are true.

get much for (something)

"Get much for ___" means to make a lot of money when you sell something. People usually use this phrase to talk about selling their used items.

Did you get much for the Toyota?

I didn't get much for it.

When you pronounce the phrase "get much for ___", the stress is on the word "get":

I didn't get much for it.

Only use "get much for" in questions and negative sentences like in the two examples above. In an example like this one:

I doubt I'll get much for it.

The sentence is negative because "I doubt" is a negative phrase. You don't use "get much for ___" in positive sentences. Instead, say something like:

I actually got quite a bit for it.

He says he got $200 for the old one.