用adv.定用adj?

1.Can you walk a bit faster.
2.Can you walk a bit more slowly.

點解第1個要用adj. – No, faster here is an adverb, not adjective. It is used to describe the verb “walk”.

唔係應該用quickly. (adv.) - quickly is an adverb, but if you want to use quick in this sentence you have to change the sentence structure to :
Can you walk a bit quicker.

點解第1個要用adj.
唔係應該用quickly. (adv.)

The word "faster" is an adverb here, not an adjective. We use an adverb here to modify the verb "walk".

The word "fast" can be used as an adjective or an adverb.
The word "quick" can also be used as an adjective or an adverb.

Therefore, it is ok to say
Can you walk a bit faster;
Can you walk a bit quicker; or
Can you walk a bit more quickly.

If you try to change them into Chinese.
1.你能走快點嗎?
2.你能再走慢點嗎?
Can you walk A BIT faster?'A Bit acts as the main-word.A Bit means a little
bit.A Bit is a phrase.Quickly is an adj. .As you put 'more',it means different.
adj.:describe something
adv.:describe an action
In 1.Can you walk A BIT faster?describing the walking speed.Someone wants others to walk faster.
After you put MORE,It must be an adv.
You may try to remember this.It's useful.