Quote Originally Posted by impulse View Post
немного/несколько
I hope you know there are countable and uncountable nouns. In English, countable nouns are used with "many" (many houses, many cars, many people) and uncountable nouns are used with "much" (much water, much sugar, much attention, much practice) etc.

So, to answer your question:

With uncountable nouns, only "немного" is possible, "несколько" does not fit:
немного воды, немного сахара, немного внимания, немного опыта.

The uncountable nouns are used in Genitive Singular after "немного".

With countable nouns, "несколько" suits well:
несколько домов, несколько машин, несколько человек, несколько слов, несколько букв.

Sometimes "немного" can be also used with them: "я купил немного яблок".

It is more difficult to say why "немного яблок" is better than "несколько яблок". But both are possible.

So, when in doubt, better stick to "несколько" with countable nouns.

Yes, and countable nouns are used in Genitive Plural.

An addition on немного/несколько.

I thought about the case with apples: "немного яблок" vs "несколько яблок". Here's what I think:
"несколько" assumes separate items (2-3-4-5, sometimes more). So, "я купил несколько яблок" is understood as if you bought just a few apples.
"немного" considers the total quantity as a single mass. So, "немного яблок" can mean 500 g or 1 kg etc.
That's why "немного яблок" is usually better unless you really mean 2-3 pieces (then "несколько" is preferred).