Когда употребляется many much a few a little some

Many много is used with countable nouns.

much много is used with uncountable nouns.

a few немножко is used with countable nouns.

a little немного is used with uncountable nouns.

Some несколько is used in affirmative sentences.

There are many apples on this apple tree. На этой яблоне много яблок.

There is much juice in the glass. В стакане много сока.

My friend knows only a few words in French.  Мой друг знает только несколько слов по-французски.

Mary can speak English a little. Мэри немножко говорит по-английски.

He just said some sentences and went away. Он только что произнес несколько предложений и ушел.