Ordinal Numbers Table

Because the rule is really about the final digit, and those numbers end in words whose histories diverged before the rule formed. Eleven and twelve are not 'one-teen' and 'two-teen' - they descend from Old English endleofan and twelf, standalone words for 11 and 12 (twelf being the root of 'dozen'), so there is no one or two at the end for st or nd to attach to. Thirteen does end in three, but it arrives as part of the -teen block, and English treats 11-13 as a unit precisely because the last-digit rule produces 'elevenst' and 'twelvend' absurdities. Hence the rule writers actually use: if the last two digits are 11, 12 or 13, use th; otherwise match the last digit (1st, 2nd, 3rd, else th).

Yes - it is the standard ordinal for zero and appears in dictionaries. Mathematics and physics need it constantly: the zeroth law of thermodynamics was named so it could precede the first law without renumbering anything, and 'zeroth-order approximation' means the crudest level of estimate. Outside technical writing, most style guides prefer rephrasing ('item zero', 'the starting point') because zeroth still reads as playful to many readers. But if a sequence genuinely begins at zero - as programming arrays and thermodynamics both do - zeroth is the correct, unembarrassed choice, and it is why this table starts its rule column there rather than pretending ordinals begin at one.

Formal and journalistic style prefers plain numerals in dates: July 4, 1776 - the ordinal is heard, not written. Speech always says 'fourth'. The suffixed form (4th of July, July 4th) is fully acceptable in informal writing, signage and speech transcription, and some publications allow it to avoid momentary ambiguity ('March 1 and 2' vs 'March 1st and 2nd' - suffixed forms survive better when a sentence stacks several dates). The forms to avoid in print are the ornamental ones: superscript 4ᵗʰ survives in advertising and word processors' autoformatting, but style manuals for news and academia reject it. Pick the house style and hold it through the document.

Three different traditions. Centuries take the ordinal in figures with a suffix or spelled out - the 21st century - never Roman numerals in modern English. Monarchs and popes take Roman numerals with no ordinal suffix: Henry VIII, spoken aloud as 'Henry the Eighth' - the th is in the speech, not the writing, which is why writing 'Henry 8th' marks a text as informal. Floors split by dialect: US buildings count from 1 at street level, so the US first floor is the UK ground floor and the UK first floor is the US second - a two-floor offset that catches travelers in lifts everywhere. Editions, volumes and chapters follow the century pattern: ordinal in figures (3rd edition) or spelled (third edition) per house style.

Cardinals count how many (one, two, three); ordinals rank in what order (first, second, third). The grammatical split follows the semantic one: cardinals behave like quantity adjectives and nouns ('three books', 'a three of a kind'), while ordinals behave like normal adjectives with the, a or a possessive in front ('the third book', 'her first attempt') - you never say 'a third book' when you mean three of them. Hyphenation is the practical trap: compound ordinals hyphenate like their cardinals (twenty-first, one-hundredth), and fractions use them differently - three-fourths is a cardinal numerator over an ordinal denominator, which is why 'fourths' has no th confusion. The test: if you can replace the number with 'last' and the sentence still works, you wanted an ordinal.