Can anyone help me about the correct usage of nd and th ?

The nth best grade
The n'th best grade
The nnd best grade

What are they called in the grammar ?
Which one of them is grammatically correct ?

Thanks in Advance

  • 'th ("apostrophe th") is never correct in ordinal numbers.
    – stangdon
    Dec 3 '15 at 15:22

They are called ordinal numbers.

The first three always have the -st, -nd & -rd ending:

1st, 2nd & 3rd.
In the same fashion, 21st = twenty-first, 22nd = twenty-second, 23rd = twenty-third, and so on.

For upcoming numbers add -th:

4th, 7th, 14th...

As for the spelling, add -th.

fourth, seventh, fourteenth.

If the number is a multiple of 10, the spelling changes:

30th = thirtieth.

  • Should I necessarily put the th in the form of superscript ?
    – Cardinal
    Dec 3 '15 at 15:43
  • 3
    To answer @Cardinal's question, no, the superscript is not necessary. "4th" is perfectly fine.
    – Catija
    Dec 3 '15 at 15:56

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .