(1)孤单(独)的(地)(without the company of anyone or anything;by oneself)：be quite～行单影只;I want to be～for a while.我想一个人呆一会儿。He has been all～since the death of his wife.妻子死后他一直孑然一身。find sb～in a place 发现某人独自在某处;leave sb～at home 把某人独自留在家里。go out/live/work all～一个人出门/生活/工作;The house stood～on the hill.那房子孤零零地立在山头上。〖同〗single，singly;〖反〗accompanied;

(2)独自(无援)的(地)(without help)：build a house/raise one's family/work out the answer all～独自盖房/养家/算出答案;bring up one's children～独自一人养大孩子;I can't do this～.我独自一人干不了。It will be difficult for one person～.这对于一个人来说是很困难的。〖反〗assisted，helped;

(3)仅仅，唯，只(only)(用于n和pron后)：God～knows.只有上帝知道。He～can do it/remembered that/knew the truth.只有他一个人干得了/记得那事/知道真相。Time～will show who is right/can cure such sorrows.唯有时间将说明谁是正确的/能治愈这种悲伤。live on bread/get along on one's wages～光吃面包/靠工资生活;be remembered/respected for that one thing～仅因那件事就将被人们铭记在心/受到人们的尊敬;

(4)孤独(lonely;lonesome)：After her husband's death she felt terribly～.丈夫去世后，她感觉孤独之极。

leave/let sb/sth alone 不打搅，听任：Leave (let) me/my things～.别碰我/我的东西。

leave/let well alone 安于现状不改动：It's better to leave well～.最好就那样吧。

let alone 更不用说：He can't speak properly，let～sing a song.他说都说不好，更不用说唱歌了。He hardly seems middle-aged，let～old.他几乎看不出到了中年，更不用说老年了。

not be alone in doing sth 并非只是一个人……：We are not ～in thinking so.不仅我们这么认为。

【辨异】alone和lonely不可混淆。alone 仅表示“单独一个”的意思，而lonely(以及AmE中的lonesome)则含有“孤独寂莫”的意思;此外还有lone，为诗歌用词。注意alone还可用作副词，其他几个不可。