Yes is a very old word. It entered English before 900, and comes from the Old English word gese loosely meaning "be it." Before the 1600s, yes was often used only as an affirmative to a negative question, and yea was used as the all-purpose way to say "yes."
* loosely ( adv. ) 大約地
* affirmative ( adj. ) 肯定的
Yes是一個很老的單字了，大約在10世紀以前就出現，而她來自於古英文中的gese，意思大概是 “ be it ” 在17世紀前，yes是給否定問句一個肯定的答案時用的，而yea則是比較通用的說法(像是現在的yes)。
This archaism is still used as the formal response meaning "yes" in the British House of Commons. It is also an accepted substitute for yea in a voice vote in the US House of Representatives. When it first entered English, it was often spelled I. Etymologists don't know where it came from, but it appeared suddenly in the late 1500s and is still with us.
* archaism ( n. ) 古語
* the British House of Commons 英國下議院
House of Lords 英國上議院
* the US House of Representatives 美國眾議院
United States Senate 美國參議院
* etymologist ( n. ) 字源學者
這個古英語在英國下議院仍然是非常正式的yes的說法，在美國的眾議院中，Aye也是一個投票時代替yea的單字，在Aye剛剛進入英文用語中的時候，她通常被拼成 ” I ”，字源學家不知道Aye是從哪個語言文化來的，但是她在16世紀突然出現，至今我們仍然在使用她。
Indubitably [in-doo-bi-tuh-buhl, -dyoo-]
The word indubitably, like many words with a negative prefix, comes from its internal root, dubitable. Strangely though, the negative variation has always been more popular than its root. They both come from the Latin word dubitare meaning "to doubt."
* prefix ( n. ) 字首
Indubitably有一個否定的字首，而字根dubitable是「可疑的、不確定的」。奇怪的是，indubitably這個否定字比dubitable還要多人使用，而indubitably和dubitable都是來自拉丁文dubitare，意思是“ to doubt ”。
OK [oh-key, oh-key, oh-key]
The origin of this common Americanism has been disputed, but it most likely came from the 1840 American presidential election in which politicos facetiously misspelled all correct as oll korrect and abbreviated it OK. The alternately spelled okay arose in the early 1900s. There are other apocryphal tales of it coming from military jargon, but we'll leave those for another day.
* presidential ( adj. ) 總統的
* facetiously ( adv. ) 滑稽的
* apocryphal ( adj. ) 作者不明的
* jargon ( n. ) 行話 ; 黑話
OK這個字的來源非常有爭議，但是最有可能的說法是1840年的總統選舉時，政客不小心拼錯了all correct ，變成oll korrect然後簡寫成OK，而OK的另一種拼法在1900年左右興起，也有其他種說法是OK來自於軍中的行話。
Sure [shoor, shur]
Sure is related to the Old French word of the same spelling which meant "safe" or "secure." The word was used to mean "safe" until the early 1500s. In the mid-1500s, sure started to take on senses of "certainly" and "indubitably," which helped introduce popular phrases such as "to be sure" and "for sure" to English speakers. The common Americanism "sure thing" arose in the 1800s.
* Americanism ( n. ) 美國風格
Sure和古法文有相同拼音，意思是「安全的」，到1500年以前這個字一直都是做為「安全」之意，到了1500年中期，sure開始有「確定地、不可懷疑地」的意思，同時也引進了to be sure和for sure這些用法給說英語的人們，美式風格強烈的用法sure thing則是在1800年開始出現。
This common casual variation of yes arose in the early 20th century in America. It is likely a drawled version of its formal cousin. Since the 1980s, its usage has risen dramatically, more than three times its previous usage.
* drawl ( n. ) 慢吞吞拉長調子的說話方式
This possible alternative spelling of yeah appeared in the 1960s, and may be a variation on the word hooray. However, it remains the least used among our yes alternatives.
* hooray ( v. ) 歡呼
And how !
If the aforementioned yes alternatives are too run-of-the-mill for your tastes, try and how! This Americanism emerged in the 1800s and is used in a number of affirming ways, along the lines of "no mistake, very much so!" "certainly!" and "you bet!"
* aforementioned ( adj. ) 上述的
* run-of-the-mill 普通的
如果上述yes的用法你覺得太普通，試試看And how吧！這種用法出現在1800年代，通常用於肯定的時候，也會加上"no mistake, very much so!" 、 "certainly!" 和"you bet!"等等語句。