Some adjectives and adverbs express qualities which are gradable. Examples are: funny, interesting, difficult, hard etc. Stories can be more or less interesting. Jobs can be more or less difficult. Other adjectives and adverbs express qualities which are not gradable. Examples are: perfect, impossible, dead, round etc. We do not usually say that people are more or less dead or perfect.
Gradable adjectives can be used with expressions like too, as, so, enough, extremely, very, rather, pretty, a little, a bit etc.
The tea is too hot.
She is very beautiful.
She looked rather unhappy.
It is quite interesting.
I am extremely grateful.
I am a little anxious about his health.
It was a bit annoying.
She is old enough to marry.
Note that a little and a bit are usually used before adjectives and adverbs expressing negative ideas.
I was a little tired.
Enough follows its adjective.
The policeman didn’t run fast enough to catch the thief. (NOT The policeman didn’t run enough fast to catch the thief.)
She isn’t old enough to have grandchildren. (NOT She isn’t enough old to have grandchildren.)
Indeed can be used after very + adjective/adverb to show emphasis.
It was very tragic indeed.
Note that indeed cannot normally be used without very.
Most is sometimes used with the same meaning as very before adjectives. This is common in a very formal style.
That was most kind of you. (= That was very kind of you.)
Not very expresses quite a low degree.
It is not very expensive. (= It is quite cheap.)
I am not very impressed with this idea. (= I am not at all impressed with this idea.)
She is not very beautiful. (= She is plain.)