My Slavic Studies

Both words can be translated as some. But that does NOT mean that they are interchangeable. Here is how to use them correctly.

Use некоторые, followed by the nominative, unless inflected by case, when you are referring to some out of a whole group of items, people, etc.

Here’s a really good sentence to help you clearly see the difference.

Некоторые были против нового закона, а другие – за него. Some (of a group) were against the new law, while others were against it.

Another example below:

Из всех учеников только некоторых поставили пятёрку. Out of all the students only some got an A.

Use несколько, followed by the genitive, when you are not referring to a part of a whole group.

Я получил несколько писем от иностранных друзей. I received some letters from foreign friends.

В очереди стояло несколько человек. There were a couple people in line.