The use of "?"

[Tom]

Hi

Could you please tell me if the following sentence seems OK without the use of the question mark? I have been using colon instead of the question mark. What is your opinion here?

[Conchita]

A colon doesn't replace a question mark, Tom. In your example, I'd leave out the colon and add a question mark at the end of the sentence, i.e. after 'adjective'.

[Prezbucky]

Yielding:

Could you please tell me the difference between "Non-gradable adjective" and "Gradable adjective"?
_________________
Billie Jean is not my lover. Hee.

[Sultano]

Gradable adjectives can be modified by degree adverbs such as "very" , "so" and "extremeley".
They can also be used in comparatives and superlatives, e.g. "small/the smallest" , "mor expensive/the most expensive".
This type of adjectives describes qualities that can be measured in degrees, such as size, beauty, age,etc.
Here are some examples with gradable adverbs:
It is a very important question.
This is room is a quite good.

Non-gradable adjectives cannot be used in comparative and superlative forms, and cannot be used with adverbs such as "very" or "extremely".
Example:
It's impossible to swim in the ocean.

[Sultano]

Just to correct something - it's a misprint.
quite good not a quite good
This room is quite good.

[Sultano]

This room is quite good.