(not used in the continuoustenses 不用於進行時態)
1 (a) [I, Tn, Tw] grasp the meaning of (words, a language, a person, etc) 懂、 理解或領會（語詞、 語言、 某人等）的意思:
I'm not sure that I fully understand (you). 我不敢說我已完全聽懂了（妳的話）. * understand the instructions, rules, conditions, etc 了解指示、 規則、 情況等 * I can understand French perfectly. 法語我完全懂. * I don't understand (a word of) what you're saying, eg because you're speaking too quickly. 妳的話我（壹個字也）聽不懂（因為妳說得太快）.
(b) [Tn, Tw, Tsg] perceive the significance or importance of (sth); perceive the explanation for or cause of 了解（某事物）的意義或重要性; 認識到...的道理或原因:
Do you understand the difficulty of my position? 妳了解我處境的困難嗎? * I don't understand why he came/what the problem is. 我不明白他為什麽來[這是什麽問題]. * I just can't understand him/his taking the money. 我真無法理解他[他為什麽要偷錢].
2 [I, Tn, Tf, Tw, Tsg] be sympathetically aware of (sb/sth); know how to deal with (sb/sth) 了解, 理解, 諒解, 同情（某人[某事物]）; 善於與（某人[某事物]打交道:
understand children, machinery, modern music 了解兒童、 機器的性能、 現代音樂 * We thoroughly understand each other/one another, even if we don't always agree. 我們彼此非常了解, 雖然有時候也有壹些分歧. * I quite understand that you need a change/your needing a change. 妳需要換換環境, 這壹點我完全理解. * He understands how hard things have been for you. 他很同情妳的艱難處境.
3 (usu fml 通常作文雅語) (a) [Tf, Cn.t] be aware from information received (that...); gather 得知; 獲悉; 推斷:
I understand she is in Paris. 我聽說她現在巴黎. * Am I to understand that you refuse? 看意思妳是拒絕了? * The situation, as I understand it, is very dangerous. 情況據我看十分危險. * I understood him to say/as saying that he would co-operate. 我認為他願意合作.
(b) [Tf usu passive 通常用於被動語態] take (sth) for granted 認為（某事物）當然如此:
Your expenses will be paid, that's understood. 妳的費用給妳付清, 當然了.
4 [Tn esp passive 尤用於被動語態] supply or insert (an omitted word or phrase) mentally 憑意會理解（省略的詞語）:
In the sentence `I can't drive', the object `a car' is understood. 在‘我不會駕駛’這句話中, 賓語‘汽車’是不言而喻的.
5 (idm 習語) give sb to understand (that)... (fml 文) cause sb to believe or have the idea that... 使某人理解、 相信或認為...:
We were given to understand that the accommodation was free. 給我們的感覺是住宿是免費的. ,make oneself under`stood make one's meaning clear 將自己的意思表達清楚: He doesn't speak much English but he can make himself understood. 他不大會說英語, 但能把自己的意思說清楚.