Questions & Answers about Я ни с кем не делюсь своими паролями.
Why do we use своими instead of моими here?
Both technically mean "my", but свой is a reflexive possessive pronoun that always points back to the subject of the sentence (Я). Whenever the subject is the owner of the object, Russian prefers using свой. Here, it takes the Instrumental plural form своими to match паролями.
Why is своими паролями in the Instrumental case?
The verb делиться (to share) requires the Instrumental case for the thing you are distributing or giving out. You can think of it as "providing someone with your passwords." Since пароль (password) is a masculine noun, its plural Instrumental is паролями, and the pronoun must match it as своими.
Why does the sentence say ни с кем instead of с никем?
When a negative pronoun like никто (no one) is used with a preposition like с (with), the preposition jumps right into the middle of the word and splits it in two. The word никто in the Instrumental case is никем, so adding the preposition с gives us ни с кем (literally "not with who").
Is it normal to have both ни and не in the same sentence?