There are four central aspects to the Latin numeral:
- The cardinal: ūnus, duo, trēs, quattuor
- The ordinal: prīmus, secundus, tertius, quārtus
- The distributive: singulī, bīnī, ternī, quaternī
- The adverb: semel, bis, ter, quater
Ordinals are derived from cardinals, and operate as declining adjectives, in the manner of bonus, -a, -um
- The suffixes attached to cardinals are often very similar to superlative suffixes (e.g. ūndēvīcēnsimus, 19th)
The Ordinals 1st-10th
- 1st: prīmus, -a, -um
- 2nd: secundus, -a, -um or alter, altera, alterum (remember alterīus is the genitive for all genders)
- 3rd: tertius, -a, -um
- 4th: quārtus, -a, -um
- 5th: quīntus, -a, -um
- 6th: sextus, -a, -um
- 7th: septimus, -a, -um
- 8th: octāvus, -a, -um
- 9th: nōnus, -a, -um
- 10th: decimus, -a, -um
A few fun notes on these:
- The cardinal prīmus is an archaic superlative from prō
- The cardinal secundus is exactly what it appears to be—the future passive participle of sequor (to follow)
- The cardinal alter is a comparative form (like with the Greek -τερος)
- The cardinal nōnus is a contraction of novenus
Cardinals 11th-19th
- 11th: ūndecimus, -a, -um
- 12th: duodecimus, -a, -um
- 13th: tertius, -a, -um decimus, -a, -um or decimus et tertius or decimus tertius
- (thus, both words decline and have three double-declining variations with 14th-19th)
- 14th: quārtus decimus
- 15th: quīntus decimus
- 16th: sextus decimus
- 17th: septimus decimus
- 18th: duodēvicēnsimus, -a, -um or octāvus decimus, etc.
- 19th: ūndēvicēnsimus, -a, -um or nōnus decimus, etc.
Cardinals 20th-100th
- 20th: vīcēnsimus, -a, -um
- 21st: vīcēnsimus, -a, um prīmus, -a, -um or ūnus et vīcēnsimus
- (thus, we have two distinct options from 11th – 19th, with (a) cardinal tens -> cardinal ones reversed or (b) ordinal ones -> cardinal tens; both terms will decline, where possible, for all cardinals 22nd-99th)
- 28th: duodētrīcēnsimus, -a, -um or the other two options
- 29th: ūndētrīcēnsimus, -a, -um
- 30th: trīcēnsimus, -a, -um
- 40th: quadrāgēnsimus, -a, -um
- 50th: quīnquāgēnsimus, -a, -um
- 60th: sexāgēnsimus, -a, -um
- 70th: septuāgensimus, -a, -um
- 80th: octōgēnsimus, -a, -um
- 90th: nōnāgēnsimus, -a, -um
- 100th: cēntēnsimus, -a, -um
A few fun notes on these:
- Again, note the distinct sets of options for the 11th-19th crowd and the 21st+ crowd: with 21st+, you get a mix of ordinals and cardinals, which can only lead to a really bad hangover…
- Whitaker’s Words suggests ūnetvīcēnsimus, -a, -um is an alternative form of 21st, though that may be Medieval only
- A few only sources suggest that the (n) in the 40th/50th/etc. is optional: quadrāgē(n)simus, -a, -um, though I should note that A&G don’t mention this
Ordinals 101st -1000th
- 101st: centēnsimus, -a, -um prīmus, -a, -um or ūnus et centēnsimus
- 113th: centēnsimus et tertius decimus or centēnsimus et decimus tertius
- (basically, we have a pattern very similar to 21st-99th, though recall that once we have three words in play, that et will only appears between the two highest denominations, so you will never see centēnsimus et decimus et tertius)
- (also, to be explicit, everything continues to decline, where possible)
- 200th: ducentēnsimus, -a, -um
- 300th: trecentēnsimus, -a, -um
- 400th: quadrigentēnsimus-, -a, -um
- 500th: quīngentēnsimus, -a, -um
- 600th: sescentēnsimus, -a, -um
- 700th: septigentēnsimus, -a, -um
- 800th: octigentēnsimus, -a, -um
- 900th: nōngentēnsimus, -a, -um
- 1000th: mīllēnsimus, -a, -um
I’ll get to the 1000+ crowd eventually, though it involves multiplicative forms, so brace yourself.
The Essential AG: 133
Latin for Addicts 