A Little : Use a little for uncountable noun to indicate a small number. For example: I owe him a little money.
A Lot : Use a lot for uncountable nouns (e.g., jam, time) to indicate many, or a large number. Notice that a lot is followed by the word of (unike a little). For example: I don’t have a lot of money.
A Few : Use a few, if the noun is countable (e.g., jars of jam, students). For example: .My neighbor let me pick a few Mangoes from his tree.