In English, ordinal numbers (also called ordinal numerals... any of the numbers that express degree, quality, or position in a series, as first, second, and third ) follow theses rules:
-st is used with numbers ending in 1 (e.g. 1st, pronounced first)
-nd is used with numbers ending in 2 (e.g. 92nd, pronounced ninety-second)
-rd is used with numbers ending in 3 (e.g. 33rd, pronounced thirty-third)
As an exception to the above rules, all the "teen" numbers ending with 11, 12 or 13 use -th (e.g. 11th, pronounced eleventh, 112th, pronounced one hundred [and] twelfth)
-th is used for all other numbers (e.g. 9th, pronounced ninth).
The letters following the number are called suffixes.
Many English Manuals of Style state: "The letters in ordinal numbers should not appear as superscripts (e.g., 122nd not 122ⁿᵈ)".
Some word processors format ordinal indicators as superscripts by default (e.g. Microsoft Word.
Some authors recommend turning off automatic superscripting of ordinals in Microsoft Word, because "no professionally printed books use superscripts".
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What kind of abbreviation do follow numbers have?
What kind of suffixes follow numbers (to form ordinal numbers)?