Мне нужно починить выключатель в коридоре.

I need to fix the light switch in the corridor.

Breakdown of Мне нужно починить выключатель в коридоре.

• я: I
• в: in
• нужно: to need
• коридор: the corridor

Questions & Answers about Мне нужно починить выключатель в коридоре.

Why does the sentence start with мне instead of я?

Because Russian often expresses need with the pattern кому-то нужно + infinitive, literally to someone it is necessary to...

So:

• мне = to me / for me
• нужно = necessary
• починить = to fix

So Мне нужно починить... literally means It is necessary for me to fix..., which is the natural Russian way to say I need to fix...

That is why Russian uses the dative case here, not the nominative я.

What exactly does нужно mean here?

Нужно means necessary / needed in this structure.

In Мне нужно починить выключатель, it works like I need to fix the switch.

A very literal breakdown is:

• Мне = to me
• нужно = it is necessary
• починить = to fix

So the whole phrase is essentially It is necessary for me to fix the switch.

Russian often uses this impersonal construction instead of a direct equivalent of English I need.

Why is починить in the infinitive?