Correct spelling, explanation: 10th is an ordinal number that appears after 8th and before 9th. It’s worth remembering that only the first three ordinal numbers look different as they are formed as 1st, 2nd, and 3rd. All the other numbers take the -th ending as in the 8th, 9th, or 10th.

Definition of 10th:
1. ordinal number – appears between 9th and 11th, its full, written form is tenth;
It’s going to be my 10th year at this company and I feel it’s high time for a change.

Expressions with 10th:
1. 10th-rate – of very poor quality;
I wouldn’t recommend you sleep at that 10th-rate motel.

Incorrect spelling, explanation: many learners and even native speakers of English get confused while forming ordinal numbers. Most of them are aware that one, two, and three – when they become ordinals – they get the forms 1st, 2nd, and 3rd. However, they also add these endings to other numbers and a common mistake is to use the form 10st, which is incorrect, instead of 10th.

Incorrect spelling

Incorrect spelling