also, too, as well, either, likewise

副詞 either:

1. after a negative statement used as an intensive meaning something like `likewise' or `also'

1. I will go on business either this week or next week.
   我將在這星期或下星期出差。
2. It's not as heavy, either.
   這也不那么重。
3. Can you speak either English or French?
   你會(huì)說(shuō)英語(yǔ)或法語(yǔ)嗎？
4. I won't trust either of the two brothers; they are tarred with the same brush.
   弟兄兩個(gè)我誰(shuí)也不相信，他們都是一路貨色。
5. A unit of measurement equal to the length of either of these instruments.
   測(cè)量單位等于這兩種工具長(zhǎng)度任一種的一個(gè)測(cè)量單位
6. Either we will find a supply, or we will make the goods.
   我們或是尋求供貨，或者自己制造。
7. You may take either of the roads.
   兩條路你隨便走哪一條。
8. If you do not go, I shall not go either.
   你不去，我也不去。

ei.ther

pron.（代詞）
The one or the other:
任一，兩方，隨便哪一個(gè)：兩者中的一個(gè)或另一個(gè)：
例句：
Which movie do you want to seeô Either will be fine.
你想看哪一部電影ô哪部都行

conj.（連接詞）
Used before the first of two or more coordinates or clauses linked byor :
或…或…，…呢還是…，要么…要么…：用在以或 連接的兩個(gè)或多個(gè)并列成分或分句的第一個(gè)之前：
例句：
Either we go now or we remain here forever.
要么我們現(xiàn)在走，要么我們永遠(yuǎn)在這呆下去

adj.（形容詞）
Any one of two; one or the other:
任一的：兩者之中任一的；一個(gè)或另一個(gè)：
例句：
Wear either coat.
穿隨便哪件衣服都行

One and the other; each:
兩方的，各自的：（兩者之中）一個(gè)和另一個(gè)；每個(gè)的：
例句：
rings on either hand.
兩只手上的都戴著戒指

adv.（副詞）
Likewise; also. Used as an intensive following negative statements:
也：同樣；也。作為強(qiáng)調(diào)成分用在否定陳述之后：
例句：
If you don`t order a dessert, I won`t either.
如果你不點(diǎn)甜點(diǎn)，我也不點(diǎn)

來(lái)源：
Middle English
中古英語(yǔ)
from Old English ôther, ôghwôther * see k wo-
源自 古英語(yǔ) ôther, ôghwôther *參見 k wo-

The traditional rule holds thateither should be used only to refer to one of two items and thatany is required when more than two items are involved:
傳統(tǒng)規(guī)則認(rèn)為either 只能用于指兩者之一， 如果涉及多于兩者的情況時(shí)，應(yīng)用any ：
例句：
Any (not either ) of the three opposition candidates still in the race would make a better president than the incumbent.
正在參加競(jìng)選的三個(gè)反對(duì)黨候選人中的任何 （不是 either ) 一個(gè)都會(huì)比現(xiàn)任總統(tǒng)干得更好。

But reputable writers have often violated this rule,and in any case it applies only to the use ofeither as a pronoun or an adjective. Wheneither is used as a conjunction no paraphrase withany is available, and soeither is unexceptionable even when it applies to more than two clauses:
但是許多著名作家經(jīng)常違反這個(gè)規(guī)則，這種情況只見于either 用作代名詞或形容詞時(shí)。 當(dāng)either 用作連接詞時(shí)， any 沒有相應(yīng)的替代詞， 所以即使用來(lái)連接多于兩個(gè)從句時(shí)，也要用either ：
例句：
Either the union will make a counteroffer or the original bid will be refused by the board or the deal will go ahead as scheduled. ·
或者工會(huì)提出一個(gè)相反的建議，或者董事會(huì)拒絕原來(lái)的要價(jià)，或者這事按原計(jì)劃進(jìn)行。

Ineither . . . or constructions, the two conjunctions should be followed by parallel elements.The following is regarded as incorrect:You may either have the ring or the bracelet (properly, You may have either the ring or the bracelet ). The following is also incorrect:She can take either the examination offered to all applicants or ask for a personal interview (properly, She can either take . . . ). · When used as a pronoun,either is singular and takes a singular verb: The two left-wing parties disagree with each other more than either does (not do ) with the right. When followed byof and a plural noun, either is often used with a plural verb:
在either … or 結(jié)構(gòu)中， 兩個(gè)連接詞后應(yīng)跟并列成分。下面這句話被認(rèn)為是不正確的：You may either have the ring or the bracelet ，正確的應(yīng)是 You may have either the ring or the bracelet （你既可以有戒指也可以有手鐲） 下面這句也是不對(duì)的：She can take either the examination offered to all applicants or ask for a personal interview。 正確的應(yīng)是， She can either take …（她可以參加提供給所有申請(qǐng)人的考試，也可以要求一個(gè)單獨(dú)面試。） 作為代名詞時(shí)，either 是單數(shù)，動(dòng)詞應(yīng)用單數(shù)形式： The two left-wing parties disagree with each other more than either does （不用 do ) with the right.（兩個(gè)左翼黨之間的分歧比任何一個(gè)與右翼黨的分歧都要大） 當(dāng)后面接of 和一個(gè)復(fù)數(shù)名詞的時(shí)候， either 經(jīng)常與動(dòng)詞復(fù)數(shù)形式配合：
例句：
Either of the parties have enough support to form a government.
這些政黨中任一個(gè)都有足夠的支持來(lái)組閣一個(gè)政府。

But this usage is widely regarded as incorrect;in an earlier survey it was rejected by 92 percent of the Usage Panel. ·When all the elements in aneither . . . or construction (or a neither . . . nor construction) used as the subject of a sentence are singular, the verb is singular:
但是這種用法通常被認(rèn)為是不正確的，在以前的調(diào)查中它被用法使用小組百分之九十二的成員所否定。當(dāng)作為句中主語(yǔ)的either…or 結(jié)構(gòu)（或 neither…nor 結(jié)構(gòu)）中的所有成分都是單數(shù)的時(shí)候， 動(dòng)詞也應(yīng)用單數(shù)：
例句：
Either Eve or Herb has been invited.
伊夫和赫伯都被 邀請(qǐng)了。

Analogously, when all the elements in theeither . . . or construction are plural, the verb is plural too:
類似地，當(dāng)所有either…or 結(jié)構(gòu)中的成分都是復(fù)數(shù)的時(shí)候， 動(dòng)詞也應(yīng)用復(fù)數(shù)：
例句：
Either the Clarks or the Kays have been invited.
克拉克全家和凱全家都被 邀請(qǐng)了。

When the construction mixes singular and plural elements, however,there is some confusion as to which form the verb should take.It has sometimes been suggested that the verb should agree with whichever noun phrase is closest to it;thus one would writeEither Eve or the Kays have been invited, butEither the Kays or Eve has been invited. This pattern is accepted by 54 percent of the Usage Panel.Others have maintained that the construction is fundamentally inconsistent whichever number is assigned to the verband that such sentences should be rewritten accordingly.As Wilson Follett put it:
然而，當(dāng)結(jié)構(gòu)中既有單數(shù)又有復(fù)數(shù)成分的時(shí)候，動(dòng)詞應(yīng)采取什么形式說(shuō)法不定。人們有時(shí)建議動(dòng)詞的人稱和數(shù)應(yīng)與離得最近的名詞短語(yǔ)呼應(yīng)；因此人們說(shuō)Either Eve or the Kays have been invited ， 而不是Either the Kays or Eve has been invited 。 這種格式被用法使用小組54的成員所接受。也有人認(rèn)為不管動(dòng)詞用什么樣的數(shù)， 這個(gè)結(jié)構(gòu)本質(zhì)上都是一致的，因此這樣的句子應(yīng)重寫。象威爾遜·伏萊特所說(shuō)的：
例句：
.This [construction] is defensible, but a workmanlike writer may put his pride in not writing sentences that need defending..See Usage Note at every ,neither ,or
.這個(gè)是站得住腳的，但是精心推敲的作者應(yīng)以寫出不需為之辯護(hù)的句子而感到驕傲。.參見 every,neither,or