sobie nawzajem in English:

Neighbours help each other.

They kissed each other.

We could tell each other some interesting things

they communicate with each other in French

The children are always arguing with each other.

Look at each other.

we don't give each other presents

we see each other every day

Good friends always help each other out.

How do you know each other actually?

The twins always wear the same clothes as each other.

We very often see each other.

Common good means that all people in a community, in a family, in a country, in EU, help each other.

I don't get on well with my dad - we don't understand each other.

помогать друг другу|to help each other