Correct spelling

61st

Correct spelling, explanation: 61st is the correct form, because we need to use the same ending as in full-word form. Thus, sixty-first will be written as a number 61st, not 61th or 63rd. Other endings, like th, are used to ordinal numbers ending with th (for example fifth or ninth).

Definition of 61st:
numeral, ordinal number between 60th and 62nd
– How old is your uncle? – It’s his 61st birthday tomorrow.
I was 61st on the list to get the tickets and I didn’t make it.


Incorrect spelling

61th

Incorrect spelling, explanation: this ending (th) is incorrect to use with number 61, because ordinal form of it is sixty-first, and first is using ending st in its numeral form. Therefore 61th is incorrect, and this number should be written as 61st, because the word form ends with st. This is why the only correct form is 61st.

Incorrect spelling

61nd

Incorrect spelling

Incorrect spelling

61rd

Incorrect spelling