According to the Collins/Cobuild Compact English Learner's Dictionary, the definition it has as an adverb is this:

ADV Little means not very often or to only a small extent.

Also at the same dictionary, it seems to be noted that the phrase "a little" as a phrase means to a small extent or degree or for a short period.

Now, which of the following it correct?

Q: Do you speak Chinese?

1. A: Yes, I speak it little.

2. A: Yes, I speak it a little

If you had to put 'a little' or 'little' in front of the noun, both 'a little' and 'little' would work well, except one is meant to say positively and the other is meant to say negatively.

A: Yes, I speak a little Chinese.

A: Yes, I speak little Chinese.
Hi Believer

Yes and little don't go together very well. Say: Yes, I speak a little Chinese.
You might say: I speak [very] little Chinese and therefore I didn't understand everything he said.

I think "a little" is used as an adverb while "little" is used as an adjective.