grammar - Too X, X enough, enough X

Can someone explain why the choices not marked as 'correct' in these fill-in-the-blank questions are wrong?

It was ___ so we didn't get it.
expensive enough
too expensive -correct
enough expensive

It's _____ to read; I don't understand it at all.
enough difficult
too difficult -correct
difficult enough

It's not _____ to sort things out.
enough late
late enough
too late -correct

It's _____ to pass.
enough difficult
too difficult -correct
difficult enough

It's _____ walk—I'll take the bus.
enough far
far enough
too far -correct
too much far

Are 'much enough' ever used together? For example,

He ate _____ and felt ill.
enough much
much enough
too much

Answer

The key point here is that if something is "too expensive", "too difficult", "too late" or whatever, then this prevents you from doing what you otherwise would.

• The car was too expensive, so I didn't buy it.


• The problem was too difficult, so I couldn't solve it.


• The party started too late, so I didn't attend.

In a sense, "enough" works the opposite way. That is, if something is "cheap enough", "easy enough", "early enough", then this enables you to do something.

• The car was cheap enough, so I bought it.


• The question was easy enough, so I posted an answer.


• The party started early enough, so I went along and stayed for a while.

Note also that when "enough" is an adverb, it follows the adjective or verb that it qualifies. When it is used as an adjective, it usually precedes the noun.

• The car had enough petrol in the tank.


• The question had enough merit to warrant being re-opened.