by mistake in English:

Tom apologized to Mary for accidentally stepping on her foot.

Manholes are round because that way they won't accidentally fall through the hole.

Tom had to have his stomach pumped because he had accidentally eaten some rat poison.

I accidentally knocked a glass over.

Loopholes are created accidentally.

Oh no, I accidentally sawed off my finger! What should I do?

It's so easy to write good example sentences, that even if we accidentally delete a few good sentences in the process of getting rid of a whole lot of bad ones, I think we could drastically improve the quality of this corpus by doing a lot of deleting.

A farm boy accidentally overturned his wagonload of wheat on the road.

Willie accidentally let off his father's shotgun and made a hole in the wall.

One of your friends accidentally picks up a very hot piece of wood.

A person was hurt accidentally during the protest.

we met accidentally in Istanbul

Malzahar is unable to make actions for the first 0.5 seconds of the ability to prevent Malzahar from accidentally cancelling his ultimate.

Have you ever accidentally taken something from a shop without paying?

Christopher Columbus once accidentally ate a sea urchin. Then, he did it a second time... intentionally.

It's a mistake.

Choosing to fight for the British proved to be a mistake.

Tom's an irritating person to work with because he'll never admit it when he's made a mistake.

A known mistake is better than an unknown truth.

The victim is thought to have taken a large quantity of poison by mistake.

The slightest mistake may lead to a fatal disaster.

Tom believes that Mary made a big mistake when she sold her father's Stradivarius.

If that man makes one more mistake, I'll fire him.

You can't mistake him for his younger brother.

It’s just a small mistake – don’t worry so much.

I tried to explain to him that we were not responsible for his mistake, but he refused to listen.

It's a very dangerous sport, where a slight mistake can lead to serious injury.

The tragic mistake affected many people.

Though Tom's English seems quite good at times, he doesn't seem to know his limitations and it's impossible to convince him that he's wrong when he makes a mistake.

The man who makes but one mistake a year because he makes but two decisions is wrong fifty per cent of the time.