これは私のではありません。

this (indicating an item near the speaker, the action of the speaker, or the current topic); this person (usu. indicating someone in one's in-group); now; here; I (me); certainly

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

I; me; private affairs; personal matter; secrecy; selfishness

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

then; well; so; well then

to be (usu. of inanimate objects); to exist; to live; to have; to be located; to be equipped with; to happen; to come about