in time， on time
(1) in time 除了译作及时，还可译作最终或总有一天。
Her helping me in time saved me plenty of time.
她的及时帮助使我省了很多时间。
(2) on time，意为准时
Everyone is requiredtobe present atthe party on time.
要求每个人准时参加聚会。
time 组成的词组已学过的还有： at a time (一次)， in no time (立刻)， at that (the) time(那时)， at times (有时)， at any time (在任何时候)等。
persuade， advise
两个词都有劝之意，persuade表示结果，advise只强调动作。
We advised (or： tried to persuade) him to stop talking，but hc refused.
我们劝(试图劝服)他别谈了但他不听。
I persuade him to stop smoking. tie now looks better.
我劝服他戒了烟。现在他看上去更健康了。
[注意] persuade 表示说服某人做/不做某事除了persuade sb. to / not to do...结构，还有persuade sb. into doing sth. / out of doing sth. 如：
He persuaded me into leaving soon.
他劝服我马上离开。
dead， deadly， dying
三个词都可以作形容词，但含义各不相同。dead意为死了，反义词是alive，表示死亡状态；deadly意为致命的表示抽象意义；dying意为临死的。
The dog has been dead for hours.
这条狗死了几个小时了。
That is a deadly snake.
这是一条致命的蛇。
The dying man tried to my mmething.
这个快死的人试图想说什么。
[注意] dead，dying可在前面加 the 作名词用；deadly还有死气沉沉之意。如：
The dead (dying) were being taken away from the spot.
当时死者 (快死的人) 正从现场被抬走。
The lecture is deadly. Many began to leave.
演讲太沉闷了。许多人开始离开。
observe， watch
当观察来讲时，observe相当于watch carefully，尤其用于实验或研究等场合。具体来说，observe含有察觉到的意思，watch意为盯着看。
watch 还含有观看(比赛、电视)等，而observe没有此意。另外，watch还有照料之意，相当于take care of。还有当心之意，相当于be careful with。
She has observed the stars all her life.
她一生都在观察星星。
Ill watch the baby while you are away.
你不在时，由我照料你女儿。
Youd better watch Mr Smith， I think he is a thief.
你最好当心史密斯先生，我想他是个贼。