Minä en soita kenellekään.

I do not call anyone.

Breakdown of Minä en soita kenellekään.

• minä: I
• soittaa: to call
• ei: not
• kukaan: anyone

Questions & Answers about Minä en soita kenellekään.

Why is the negative verb en used instead of just adding not to the main verb?

Finnish forms negation with a separate negative auxiliary verb that is conjugated for person/number: en, et, ei, emme, ette, eivät. The main verb then appears in a special form called the connegative (it doesn’t show person endings).
So minä en soita = I + (I do not) + call/play, where soita is the connegative of soittaa.

Why is the main verb soita and not soitan?

Because in a negative sentence, the main verb usually loses the personal ending and becomes the connegative.
Affirmative: minä soitan (I call / I play)
Negative: minä en soita (I don’t call / I don’t play)

Is minä necessary here, or can it be omitted?

It can usually be omitted. Finnish verb forms already show person, and the negative verb does too.
En soita kenellekään. is the most neutral way to say it.
Including minä often adds emphasis/contrast, like I (as opposed to someone else) don’t call anyone.

What does kenellekään mean grammatically, and why that form?