1.be doing...when 正要做某事時(shí)，突然……
【例句】They were talking when the teacher came in. 老師進(jìn)來的時(shí)候他們正在講話
【拓展】be doing…when suddenly 某人正在做……突然……
2.be doing 表達(dá)某種語氣、感情，如喜愛、贊美、厭惡、痛恨、批判等
【例句】He seems to be doing nothing, but actually he is just biding his time.
他看上去無所事事，其實(shí)卻在等待良機(jī)。
【總結(jié)】be doing按計(jì)劃、安排即將做。常用動(dòng)詞有g(shù)o, start, leave, reach, arrive, return, come, move.
例如：They are moving to a new flat next week.
另外有一種說法是：“表示在近計(jì)劃或安排要進(jìn)行的動(dòng)作，常限于go, come, leave, start, arrive, return, work, sleep, stay, do, have, wear等表移動(dòng)、方向的詞”
3.be done away with 結(jié)束、結(jié)果
【例句】Opium smoking has been done away with in your country. How did you manage it? 你們國家己經(jīng)沒有抽鴉片的了。這一點(diǎn)你們怎么辦到的?
【總結(jié)】及物的動(dòng)詞短語也可以構(gòu)成被動(dòng)語態(tài)，此時(shí)要注意 切勿丟掉與動(dòng)詞連用的介詞或副詞。
4.be dressed in 穿……
【例句】The girl was dressed in brown from top to toe. 那女孩從頭到腳穿著一身棕色的衣服。
【總結(jié)】be/get dressed (in) 意為“穿著...”，如果后跟賓語，則in不可少。如：She is dressed well today. 她今天穿得很漂亮。She is dressed in a new skirt. 她穿著一條新裙子。是穿的狀態(tài).
【拓展】①dress是及物動(dòng)詞，意為“為...穿衣”,用法是dress sb，如：The babysitter dresses the baby everyday.保姆每天都要給寶寶穿衣。
②be dressed in 只有穿著的意思
be dressed up in 是盛裝打扮
③put on-表示動(dòng)作
try on-試穿
wear-表示狀態(tài)