These very common words are frequently confused in everyday speech. Here is a helpful guide to help you avoid this confusion.
A Little/Little
When we use 'a little' or 'little', the subject of our sentence should be singular, or an uncountable noun or collection of things indicated by a collective noun (which you treat as a singular word). Both are used to refer to a small quantity of something, but there is a subtle difference in meaning and usage between the two.
A little = some
Little = hardly any
As we can see, without the article (in this case 'a'), 'little' does not mean anything drastically different, but it tends to be used in a negative context. For example:
'A little' can also be used as a pronoun when your meaning is obvious from the context of the conversation.
'Little', on the other hand, is not common without a noun unless used in a more formal context.