two
n.n. the number that comes after one and before three. You use it to talk about a pair of things.
n. the cardinal number equivalent to the sum of one and one. It functions as a determiner when preceding a noun or as a noun when referring to the digit itself.
I have two sisters and one brother.
The director asked the actors to perform the scene two more times to get the lighting right.
The study compared two distinct groups of participants to determine if the new medication had a statistically significant effect on recovery times.
PIE word *dwóh₁ From Middle English two, twa, from Old English twā, feminine and neuter of twēġen (whence twain), from Proto-West Germanic twai-, from Proto-Germanic twai, from Proto-Indo-European *dwóh₁. Cognates Cognate with Scots twa (“two”); North Frisian tou, tuu (“two”); Saterland Frisian twäin, two (“two”); West Frisian twa (“two”); Dutch twee (“two”); Low German twee, twei (“two”); German zwei, zwo (“two”); Danish and Norwegian to (“two”); Swedish två, tu (“two”); Icelandic tvö (“two”); Faroese tvey (“two”); Latin duō (“two”); Ancient Greek δύο (dúo, “two”); Irish dhá (“two”); Lithuanian dù (“two”); Russian два (dva, “two”); Albanian dy (“two”); Old Armenian երկու (erku, “two”); Sanskrit द्व (dvá, “two”); Tocharian A wu, Tocharian B wi. Doublet of duo. See also twain. Unrelated to similar words in Austronesian languages such as Malagasy roa; Tagalog and Cebuano dalawa; West Coast Bajau and Minangkabau duo; Buginese ᨉᨘᨓ (dua); Indonesian, Malay, Iban, Iranun, Ilocano, and Sundanese dua; Fijian, Māori, Rapa Nui, and Rotuman rua; Tongan and Niuean ua; Wallisian, Samoan, and Hawaiian lua; and South Marquesan 'ua; which originated from Proto-Austronesian *duSa.
When used as a determiner, it precedes the plural form of a countable noun.