Correct spelling, explanation: should is a native English word based on the Old English scholde. You can probably see some similarities between these two. Most notably, ol in the middle became oul, and ch was shortened to h, but when you considered pronunciation standards back in the day (closer to German pronunciation) to the current one, you can see why should changed the way it did.

Definition of should:
verb
1. Used to express the necessity to do something
You should always remember to brush your teeth twice a day.
2. used to express something will probably happen
There are a lot of hotels in the area so there should be no problem with finding a place to stay.

Idioms with should:
that should do it – used to express that a finished (or soon-to-be-finished) action will probably be enough
I’ve been cleaning up all day, now I just have to vacuum and that should do it.

Incorrect spelling, explanation: should, which is the correct spelling of shoud is a word based on the old English Scholde. This is one reason why l should stay where it is. If you’re unsure, compare should to the related word shall, or to words built on a similar basis, such as could or would.

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling