Correct spelling, explanation: 22nd is twenty-second written as a number. It is an ordinal number, which is most frequently used in official documents. It’s important to mention that 22nd has the same ending as 2nd as the first three ordinal numbers are 1st, 2nd, and 3rd, the same happens with 21st, 22nd, and 23rd.

Definition of 22nd:
1. ordinal number – a number which appears after 21st and before 23rd, it is twenty-second written as a number,
Her 22nd birthday was a huge disaster as it was supposed to be a barbecue, but the weather was awful and hardly anyone came.

Collocations with 22nd:
A few popular collocations with 22nd are: 22nd place, 22nd day, 22nd of September
John got into the university in 22nd place, which is quite an achievement, taking into consideration that there were so many candidates.
The 22nd day of August will be our wedding day, which is something I’m really looking forward to.
Let’s set the meeting for the 22nd of September as it’s the only day I’m free this month.

Incorrect spelling, explanation: the main ending for ordinal numbers is -th, e.g. it occurs with fourth, seventh, or eighth. However, one, two, and three, when they become ordinal numbers, have different endings as these are 1st, 2nd, and 3rd. As a result, the ordinal number for 22 is 22nd. Some English users, however, misspell 22nd as 22st, which is incorrect.

Incorrect spelling

Incorrect spelling