中考化学辅导资料:化学方程式5
跟碱有关的化学方程式:NaOH+HCl(或HNO3、H...
Already and Yet - Used with the Present Perfect
already和yet——用于现在完成时态
Both already and yet refer activities around the present moment in time.[/en
]二者指的都是现在某个活动。
[en]I have already finished my lunch.
我已经吃完午饭了。
Have you seen Tom yet?
你看到汤姆了吗?
They haven't visited Rome yet.
他们没有去罗马。
Already - Referring To a Past Event
指过去的事件
Already is used to something that happened before the moment of speaking. However, it refers to something that affects the present moment in time. Let's take a look at a few examples:
already用来指发生于说话之前的事件。但是,它指代的是对现在产生影响的事件。下面我们看看几个例子;
I have already finished the report.
我已经完成报告了。
This sentence could be used to express the idea that I finished the report and it is ready to read now.
该句话可以用来表示,我完成了报告,现在可以看了。
She has already seen that film.
她已经看过那个电影了。
This sentence might express that the woman saw the film in the past, so she has no desire in the present moment to see the film.
该句话可以用来表示,这位女士之前看过这场电影,所以她现在不想再看了。
They have already eaten.
他们已经吃完了。
This sentence would probably be used to state that they are no longer hungry in the present moment.
该句话可以用来表示,他们现在不饿了的意思。
The key to using 'already' is to remember that an action that has happened in the past - often in the recent past - affects the present moment or a decision about the present moment in time and therefore is used with the present perfect tense.
already用法的关键所在就是,记住这个动作是发生在过去——通常是最近——对现在或现在的决定产生影响,因此要用现在完成时态。
Already - Sentence Placement
句中的位置
Already is placed between the auxiliary verb 'have' and the participle form of the verb. It is used in the positive form and should not be used in the negative.
Already位于助动词have和动词的分词形式之间。它用于主动语态,而非被动语态。
Subject + have / has + already + past participle + objects
主语+have/has+already+过去分词+宾语
I have already seen that film.
我已经看过这个电影了。
Mary has already been to Seattle.
玛丽已经去过西雅图了。
NOT!!
错误用法:
I have seen already that film.
我已经看过这个电影了。
Already is generally not used in the question form. However, when expressing surprise in a rhetorical question it is sometimes used in informal conversations.
already一般不用于疑问句中。但是,当以反问的形式表达惊讶时,already可以用于一些非正式对话中。
Have you already eaten?!
你已经吃完了?!
Have you already finished?!
你已经完成了?!
Yet - Asking Questions
用于疑问句中
Yet is used to check whether something has occurred up to the present moment.
yet用于确认某事目前有没有发生。
Have you seen that film yet?
你看过那个电影吗?
Has Tim done his homework yet?
蒂姆做完作业了吗?
You may notice that there is a similarity to the use of 'ever' in the present perfect to ask a question:
你可能会注意到,这种用法与现在完成时态中关于ever的疑问句类似:
Have you ever seen that film?
你看过那个电影吗?
Have you seen that film yet?
你看过那个电影吗?
These questions are very similar in meaning, but yet is generally used to ask about something closer to the present moment. Yet is often used when someone expects something to have occurred recently.
这些问句在意义上十分相似,但是yet一般用于询问不久前发生的某件事。Yet常用于某人期望最近发生某事。
Have you finished that report yet? - In this case a colleague expects the report to be finished soon.
你完成报告了吗?——在这种情况下,同事是希望报告可以很快完成的。
NOT
错误用法:
Have you ever finished that repot? - Ever is used to ask about experience in general, not whether something specific has been completed recently.
你完成报告了吗?——ever一般用来询问是否经历某事,而不是具体的某件事最近是否完成了。
Yet - Question Placement
句中的位置
Yet is always placed at the end of a question. Notice that yet is not used with question words as questions with yet are yes/no questions.
yet常位于疑问句的末尾。注意:yet不会和疑问词搭配在一起,因为带有yet的疑问句都是关于是/否的句子。
Have + subject + past participle + objects + yet + ?
have+主语+过去分词+宾语+yet+?
Examples:
例子:
Have you finished that report yet?
你完成报告了吗?
Has she bought a new car yet?
她买了新车了吗?
Yet - Negative Form
用于否定句中
Yet is also used in the negative to express that something that is expected has not yet happened. In this case, yet is placed at the end of the sentence.
yet也可以用于否定句,用来表示期望某事不要发生。在这种情况下,yet位于句末。
Subject + have not / has not + past participle + objects + yet
主语+have not/has not+过去分词+宾语+yet
She hasn't finished the report yet.
她没有完成报告。
Doug and Tom haven't telephoned yet.
道格和汤姆没有通电话。
Already - With the Past Perfect
用于过去完成时
Already can also be used with the past perfect to express that something had happened before something else. It is used in the same senses explained previously with present perfect usage.
already也可以用于过去完成时,用来表达某事发生于另一事件之前。在之前现在完成时的句子中,也可以使用already。
She had already eaten when he arrived.
当他到达时,她已经吃完了。
Jackson had already done his homework when he was asked for help.
当他求助时,杰克逊已经完成作业了。
Already - With the Future Perfect
用于将来完成时
Already is also used with the future perfect to express that something will have been completed before something else occurs.
already也可以用于将来完成时,用来表达某事在另一事之前发生。
She will have already finished the paperwork before the meeting.
她在会议之前就可以完成文书工作。
Frank will have already prepared the report by the time the boss asks for it.
在老板问起之前,法兰克就会准备好报告。