0 abbreviation for instant messaging -- 短信;即时消息(instant messaging的缩写)
1 abbreviation for intramuscular -- 肌内的(intramuscular的缩写)
2 short form of I am -- (I am的缩略形式)
I'm so happy for you! 我真替你高兴!
I'm determined to get a better job.
I've told Steve I'm not interested, but he keeps asking me out.