A cheque, or check, is legal tender for most purposes; in other words, it equals money, just as a pound or dollar coin does.

Probably nothing at all will happen if a cheque, or check, contains a genuine spelling mistake.

The consequences of incorrect spelling when writing a cheque, or check, would depend entirely on the circumstances, whether the money to be paid by the cheque is in dispute, and so on.

A genuine mistake in spelling would make no difference, since it will be obvious that the mistake is genuine.

If someone has deliberately misspelled, say, the name of the payee in order to stop the cheque and claim they've done so because they remembered they'd spelt the payee's name wrong (and this has been tried!) they'd be unlikely to get away with it. If they need more time to pay, they'd be better off to negotiate terms with the person or business they owe the money to.

If you receive a cheque on which your name has been misspelled, and it clearly is a misspelling, not another name entirely, just pay it into your bank in the normal way. The chances of a bank worker noticing the mistake are small, and even if they do notice, it's easily established whether the cheque is really intended for you.

There's not much point discussing a possible misspelling of the amount. The amount the cheque is made out for will be written in both words and in numerals, so there's no chance of getting it wrong. If someone's written 'on thousand', or 'one tousand' or 'one thusan' and also 1,000, the bank should feel confident they mean 'one thousand' of whatever currency is being paid.

If you'd like to give a more specific example, it might be possible to give a more helpful answer.