Incorrect spelling

3th

Incorrect spelling, explanation: 3th is incorrect because third (3rd) doesn’t end with -th but with -rd so such suffix must be added to the number when creating an ordinal form of it. -th is used with numbers ending with it, for example eleventh (11th), fifty-fifth (55th), etc. The correct form is thus 3rd.


Correct spelling

3rd

Correct spelling, explanation: the correct form of this ordinal number is 3rd because suffixes of ordinal numbers are the same as the ending sound of the word form; therefore third is 3rd, not 3th. This mistake may be caused by the fact that th is the most common suffix in ordinal numbers. There are however three irregular ones: -st, -nd, and -rd.

Definition of 3rd:
numeral, ordinal number between 2nd and 4th
I got 3rd place but I was still very proud of myself.
It’s 3rd time this week you’re late!


Incorrect spelling

3nd

Incorrect spelling

Incorrect spelling

3st

Incorrect spelling