Difference between Enough to and Too…to

Enough to shows sufficiency. It has a positive meaning.

Verb pattern: Subject + verb + adjective / adverb / noun + enough + to-infinitive

He is strong enough to lift that box.
The boy wasn’t clever enough to understand that.
We are not rich enough to buy a car.
He didn’t run fast enough to catch the thief.
Was he foolish enough to trust her?

Note that enough comes after the adjective or adverb it modifies.

She is old enough to be a grandmother. (NOT She is enough old to be a grandmother.)
He was kind enough to lend me a pound. (NOT He was enough kind to lend me a pound.)

Too…to

Too-to shows undesirable excess. It has a negative meaning.

Subject + verb + too + adjective / adverb + to-infinitive

It was too hot to go out. (= It was so hot that we / he / they didn’t go out.)
He was too tired to walk. (= He was so tired that he couldn’t walk.)
The coffee was too hot for me to drink. (= The coffee was so hot that I could not drink it.)
She has become too fat to wear her old jeans.
You have become too much of a nuisance to put up with.

Notes

Too does not mean very.

She is very beautiful. (NOT She is too beautiful.)
She is too fat. OR She is very fat.

In an informal style, however, too is often used instead of very.

You are too kind. (Less formal than ‘You are very kind’.)