More on "Something" and "Anything"

Words like 何か and 何も are used in sentences in place of the particles は, が, and を. However, a bit of a strange phenomenon occurs when it comes to the particles に,で, and へ. I'm going to list the words in their respective forms to make this easier.

だれか
どこか

だれにも
どこにも

だれでも
どこでも

ーー
どこへも

The first group is just the "some" form of the words with か added to the end. The other groups are the forms of the words used when they are placed in a sentence with に,で, or へ. The particle is jammed into the middle of the original word ( だれも or どこも ). It is not placed after the word, as it usually is.

だれ__も -> だれにも
どこ__も -> どこにも

Since this is a difficult concept to explain, I'm just going to give a few examples with these words. The last one is partially from Genki.

パーティに行った時に、だれにも会わなかった。
I didn't meet anybody when I went to the party.

リーさんはフランスに来た時に、どこへも行かなかった。
When Lee-san came to France, he didn't go anywhere.

ううん、何もしなかった。
No, I didn't do anything.

I think this is something I need to reinforce with reading practice, because it's tough to understand with so little context.