Appendix:English ordinal numbers

English has several series of ordinal numbers, representing position in a sequence: a main series of commonly used adjectives, beginning, , ; a series of Latinate adjectives, beginning , ; and a series of Greek prefixes, beginning ,.

The main series is formed regularly from lower cardinal numbers, starting with the single digits, by replacing the last word with the corresponding ordinal (e.g., “twenty-first”, “hundred-twentieth”), or suffixing to a single word (e.g., ), or  for the multiples of ten ending in  (e.g., ). The Latinate series is formed from Latin numbers, but numbers above are very rare, and frequently confused with arities, which also end in -ary but are based on Latin distributive numbers, not ordinal numbers. The Greek series is quite technical, and obscure beyond, which is itself uncommon.