- Roman numerals,
- ordinal numbers, and
- cardinal numbers.
Roman Numerals:
The forms we use in English, starting with 1,2,3, etc. are numerals. They happen to be based on Arabic numerals (or Hindu numerals), and were not used by the ancient Romans. Instead, the Romans, like the Greeks, used select letters of their alphabets. Roman numerals include the letters I, V, X, L, C, D, and M. There is not a symbol for zero in the Roman numeral system.
Ordinal Numbers:
Ordinal numbers are ordered numbers. The number doesn't refer to a quantity or value, but to rank. In English, our ordinal numbers begin with first, second, and third (Latin: primus, secundus, tertius). You might win a blue ribbon or a gold medal for first place. Second and third place win baser medals. These ordinal numbers are adjectives. In Latin, adjectives must be modified (declined) to agree with their nouns.
Cardinal Numbers:
Cardinal numbers are counting numbers. When we count objects, we say "one, two, three..." in English. In French, we would say "un, deux, trois..." In Latin, we would say "unus, duo, tres..." but we would have to check on agreement with the object counted for these three forms.
Other Numbers:
- semel (once),
- bis (twice),
- ter (thrice),
- quater (four times), and
- quinquie(n)s (five times).
- singulî (-ae, -a),
- bini,
- terni,
- quaterni,
- quini,
- seni,
- septeni,
- octoni,
- noveni, and
- deni.
