Meaning of yī:
伊
surname Yi; abbr. for 伊拉克[Yi1la1ke4], Iraq
Tā xìng Yī, shì wǒ de hǎo péngyǒu.
他姓伊，是我的好朋友。
His surname is Yi, and he is my good friend.
yī lǎng shì yī gè yǒu qù de guó jiā.
伊朗是一个有趣的国家。
Iran is an interesting country.
abbr. for 伊朗[Yi1lang3], Iran; (old) third person singular pronoun ("he" or "she"); second person singular pronoun ("you"); (May 4th period) third person singular feminine pronoun ("she"); that (preceding a noun)
Yīlǎng shì yī gè wèiyú zhōngdōng de guójiā.
伊朗是一个位于中东的国家。
Iran is a country located in the Middle East.
Yī bù xiǎng qù cān jiā pài duì.
伊不想去参加派对。
She does not want to attend the party.
Yī shì wǒ zuì hǎo de péngyǒu.
伊是我最好的朋友。
You are my best friend.
Yī zhèngzài yuèdú yī běn yǒuqù de shū.
伊正在阅读一本有趣的书。
She is reading an interesting book.
Zhè shì wǒ dú guò de zuì hǎo de yī běn shū, yī de gùshì qíngjié kòurénxīnxuán.
这是我读过的最好的一本书，伊的故事情节扣人心弦。
This is the best book I've read; its storyline is captivating.
(Classical Chinese) introductory particle with no specific meaning
Yī duì zuótiān de shìqíng háowú jìyì.
伊对昨天的事情毫无记忆。
He has no memory of the events from yesterday.
