机 (jī) is a noun meaning "machine" and frequently appears as a suffix in compound words. Common examples include 计算机 (computer), 飞机 (airplane), and 手机 (mobile phone). It rarely stands alone and is almost always part of a compound.
他在一家大公司修理各种机器,包括打印机和复印机。
tā zài yì jiā dà gōngsī xiūlǐ gè zhǒng jīqì, bāokuò dǎyìnjī hé fùyìnjī.
He repairs various machines at a large company, including printers and copiers.
现在的年轻人离不开手机和计算机。
xiànzài de niánqīngrén lí bù kāi shǒujī hé jìsuànjī.
Nowadays young people can't live without their phones and computers.
飞机马上就要起飞了,请系好安全带。
fēijī mǎshàng jiù yào qǐfēi le, qǐng jì hǎo ānquándài.
The plane is about to take off, please fasten your seatbelts.