Incorrect spelling

43th

Incorrect spelling, explanation: this is an incorrect form since number three in its ordinal form is third so we use suffix -rd at the end of the numeral form. Therefore ordinal form of 43 is 43rd (forty-third), not 43th (because third ends with -rd).


Correct spelling

43rd

Correct spelling, explanation: for ordinal numbers in numeral form we use suffixes which are at the end of written form: forty-ninth is 49th, twenty-first is 21st etc. Usually ordinal numbers end with -th suffix, however not all of them, including third (from ordinal number three), which uses the suffix -rd. That is why 43rd is the correct form and not 43th.

Definition of 43rd:
numeral, ordinal number between 42nd and 44th
For my husband’s 43rd birthday we went to Barcelona.
Tomorrow is my grandparent’s 43rd wedding anniversary.


Incorrect spelling

43st

Incorrect spelling

Incorrect spelling

43nd

Incorrect spelling