1.sink的基本意思是“下沉”,指逐渐下降地运动,尤指物体在空气或水中垂直下降,常指降至于地平面或水平面之下,即全部“浸没”。引申可表示“(日、月等)落下”“(头、目光等)下垂”“衰退”“(地面,建筑物等)下陷”“挖掘(井等)”“埋下”“(价格)降低”“(声音、火、风等)降低”等。引申用法中强调缓慢、逐渐地下落,而不含或少含有“浸没”意味。
2.sink既可用作及物动词,也可用作不及物动词。用作及物动词时接名词、代词作宾语。可用于被动结构。
3.sink作“下沉”解时不可以同down连用,作“落下”解时可以同down连用,表示“降到下一层的水平位置上”。

sink back(v.+adv.)
1.重重地往后坐下sit back
▲sink back into sth
Thankfully, he sank back into his comfortable chair; someone else would do the job.那件工作将由另一个人去做; 他颇感欣慰地坐到他那把舒适的椅子上。
2.退下fall back
▲sink back
She sank back, unwilling to face her father's anger.她退了回去,不愿看着父亲发火。

sink below(v.+prep.)
落到…下 fall below sth
▲sink below sth
The moon sank below the hills.月落山下。
As he turned homeward, the sun was sinking below the western horizon.他转身返家时,太阳正徐徐西沉。

sink in(v.+adv.)
下陷; 被吸收,被了解go below; be absorbed, understood or acknowledged
▲sink in
His eyes have sunk in.他的眼睛凹下去了。
He looked very pale; his cheeks had sunk in.他脸色苍白,双颊陷了下去。
It took a long time for the bad news to sink in.人们花了很长时间才弄明白这个坏消息。
Your warning didn't sink in. You may have to talk to him again.你的警告他没听进去,恐怕你得再跟他谈谈。
I think it has finally sunk in that she must be more careful; she won't forget her passport again!我想她终于明白了以后必须更加小心才是,她再也不会忘记她的护照了。

sink into(v.+prep.)
1.渗入,陷入,沉入,进入put, force, or go below (a surface) or into (a solid)
▲sink into sth
It will take a little time for the rain to sink into the dried earth.要使雨水渗入干土需要一些时间。
He was very tired and sank into a chair.他非常疲倦,躺靠在椅子上。
The facts don't seem to sink into his head.他似乎没有牢记这些事实。
Let this lesson sink into our heart.让这个教训铭记在我们心中吧。
At last the child sank into a deep sleep.孩子终于沉睡了。
Don't allow yourself to sink into grief, it can do no good.不要使自己陷入悲哀之中,这样一点好处也没有。
It is really a sad thing to see them sink into such moral degeneracy.看他们堕落到这个地步,真是一件可悲的事。
He sank further into debt.他进一步陷入债务中。
She sank into unconsciousness.她渐渐失去了知觉。
▲sink sth into sth
He sank his fork into the meat to see if it was well cooked.他把叉子叉进肉里,检查一下火候够不够。
Sink the fence post carefully into the soil.把篱笆桩小心地打入地里。
2.把…投入…put a lot of money into a business, property, deal, etc.
▲sink sth into sth
He sank all his savings into the firm.他把他所有的积蓄都投入了这家公司。
I've sunk all my money into a new house.我投了所有的钱去买一幢新房子。
He has sunk half his fortune into a new business undertaking.他已把一半财产投资于一个新企业。

sink down(v.+adv.)
降低 descend
▲sink down
The flames at last sank down and the fire went out.火焰最后微弱下来,火就灭了。
Their standard of living steadily sank down.他们的生活水平不断下降。
Her head sank down, tears welled up in her eyes.她的头低了下来,眼中涌出了泪水。

sink or swim
自己去闯 make a living wandering; blaze a trail
He must sink or swim by his own efforts now.现在得靠他自己去闯了。
He was left by his family to sink or swim by himself.他家里让他一个人自己去闯。

sink to(v.+prep.)
低到 fall to sth
▲sink to sth
His voice sank to a whisper.他的声音低到成为耳语。
She fainted and sank to the ground.她昏倒在地上。
The morale of the enemy forces sank to a very low level.敌军士气十分低落。
A bite from a thief sinks to the bone.贼咬一口,入骨三分。

用作不及物动词
▲S+～(+A)
The ship struck the rocks and sank.那船触礁沉没了。
This rubber ball won't sink; it floats.这个橡皮球不会沉,它浮着。
The sun is sinking in the west.夕阳西下。
The foundations have sunk.地基下陷了。
The ground suddenly sank.地面突然陷下去了。
His heart sank.他感到沮丧。
His heart sank at the thought.想到这个他情绪低落。
The patient is sinking fast and won't live much longer.病人迅速衰弱下去,不会活多久了。
The prices are sinking.物价下跌了。
Her voice had sunk even lower as she went on.她的声音越说越低。
The population of the island has sunk from 5000 to 3000.这个岛上的人口从5000下降到3000。
用作及物动词
▲S+～+n./pron.
The big guns sank the ship.大炮击沉了那艘船。
The enemy sank a merchant ship. It sank with the loss of 200 lives.敌人击沉了一艘商船,随着该船的沉没有200人丧生。
Our aircraft sank the submarine by dropping depth bombs.我们的飞机用深水炸弹炸沉了潜艇。
A little leak will sink a great ship.小漏洞能使大船沉没。
They sank a well in the garden.他们在花园里挖了一口井。
The workers sank a mine shaft at the foot of the mountain.工人们在山脚挖了一个矿井。
They are going to sink fence posts around the house.他们打算围绕着房子打篱笆桩。
They sank the post one foot deep in the ground.他们把这根柱子在地下埋了一英尺深。
Let us sink our differences, and work together.让我们摒弃分歧,一起工作吧。
The lack of money will certainly sink our plan.资金短缺准会毁了我们的计划。
◇ 用于be ～ed 结构
The enemy ship was sunk by a shell.敌舰被炮弹击沉。
This was how the first oil well was sunk.第一口油井就是这样打出来的。
其他
▲v-ing as Attrib.
They tried in every way possible to rescue the sinking boat.他们想尽一切办法来援救这艘下沉的船。

sink, descend, drop, fall
参见drop条。
下面两句意思不同：
His eyes sank.
他目光下垂。
His eyes sank in.
他眼睛下陷。

太阳在西边徐徐落下。
［误］  The sun was sinking down the west.
［正］  The sun was sinking in the west.
［析］  sink作“下沉”解时已经含有“下”的意思,故不可再用down。

sink的过去式还有另一种形式sunken,只用作形容词,修饰名词,而不用于完成时中。

1.sink用作名词时意思是“水池,水槽”,多指厨房中的洗涤槽。
2.sink与介词of连用可表示“藏污纳垢的场所,窝”,多用在文学用语中。

The dirty dishes are in the sink.脏碟子在洗涤槽中。
She accused a sink of corruption.她指出了腐化的渊薮。
I commit myself to make up for past mistakes to fight a sink of corruption and injustices.我决心弥补我过去的错误,去同贪污腐化的渊薮和各种不公正的现象作斗争。
The part of the town is a sink of iniquity.小城的那一部分是一个藏污纳垢的场所。

［同义词］ v.  abandon, abate, abolish, bore, decay, degrade, suppress, worsen
［反义词］ v.  float, rise, uplift
［词源］  ＜古英语sincan(下沉)