niezobowiązujący in English:

The fact is apparent to the most casual observer.

A casual remark can hurt someone.

casual clothes

I get the impression we will pay for this casual approach sooner or later.

Even casual observers realize one striking thing about drones — they often have four propellers (but can have anywhere from three to eight) unlike traditional RC helicopters, which have only one main rotor.

The verb 'help' takes to-infinitives and bare infinitives but bare infinitives are said to be the most common in casual text; as also used in this example sentence.

Up to now we've been taking a casual relaxed attitude toward our relationship but I want to start looking at us more critically.

That topic is too intimate to share with casual acquaintances.

I want our relationship to be casual - let's not talk about getting married just yet!

The interview took place around the kitchen table and was very casual.

　His voice was casual, but Harry couldn't help noticing that Mr. Weasley's ears had gone red, just like Ron's did when he was under Pressure.

Mono-casual, that is, caused by one thing.

It won't be an elegant party, so you can put on something casual.

Why can female staff in Canterbury wear casual clothes but the men have to wear shirts and ties?

You really need to take your studies more seriously if you want to succeed – your attitude is far too casual