Only & Just

Just

Exactly

That's just what I needed!

Recently

She's just arrived

Barely

I just have 100 yuan

Simply

I just drink black coffee

Emphasis

You're just great!!!!!!!!!!!!!

Softener / Polite Form

Just help yourself to anything you like. Could I just ask you a question?

Only

solely/exclusively

Recently (same as just)

It was only discovered last year

Negative/unfortunate

More money will only bring more problems

Single/ Alone in its kind

I've only run one full marathon

use as conjunction, meaning but, however

You just started learning English, only you sound fluent because you're so confident.

it was used to be in conversation but not much used in writing