在英語中，合同一般稱為contract，協(xié)議一般稱為agreement。
何謂“contract”?
1999年中國(guó)《合同法》第二條對(duì)contract定義為： a contact in this law refers to an agreement establishing, modifying and terminating the civil rights and obligations between subjects of equal footing, that is, between natural persons, legal persons or other organizations”。根據(jù)這一定義，合同平等主體之間設(shè)立的確定民事權(quán)利和義務(wù)的協(xié)議。 ，
steven h. gifts編著的“law dictionary”中將contract 定義為“contract is a promise, or a set of promises, for breach of which the law gives remedy, or the performance of the which the law in some way recognize as a duty.”根據(jù)這一定義，合同是一種承諾，違反承諾可以得到法律救助，某種意義上法律將履行該承諾看做是一種補(bǔ)償。
l.b curzon 在其編撰的字典“a dictionary of law”給contract的定義：“contract is a legally binding agreement”根據(jù)這一定義，合同就是有法律約束力的協(xié)議。
綜合起來，有一個(gè)相同點(diǎn)，就是“contract is an agreement”，即可將合同說成是“an agreement which binds the parties concerned”或者說合同說成是“an agreement which is enforceable by law”， 也可以說：contracts are promises that the law will enforce。 ，
何謂“agreement”? ，
l.b “a consensus of mind, or evidence of such consensus, in spoke or written form, relating to anything done or to be done.”
根據(jù)這一定義，協(xié)議是對(duì)已經(jīng)做或準(zhǔn)備做的相關(guān)事宜，經(jīng)過談判、協(xié)商后〉靡恢亂餳鑰諭坊蚴槊嫘問階齔齙腦級(jí)ā?nbsp;
black "law dictionary"有兩個(gè)定義。一個(gè)是：“a concord of understanding and intention between two or more parties with respect to the effect upon their relative rights and duties, of certain past or future facts or performance”根據(jù)這一定義，協(xié)議即雙方或多方京某些過去或?qū)砟承┦聦?shí)的相關(guān)權(quán)利、義務(wù)或相關(guān)權(quán)利、義務(wù)的履行而達(dá)成的一致理解和愿望。
另一個(gè)是：“the consent of two or more persons concurring respecting the transmission of some property, right or benefits, with the view of contacting an obligation, a mutual obligation.”根據(jù)這一定義，協(xié)議即兩個(gè)或多個(gè)當(dāng)事人，為了約定單方責(zé)任或相互責(zé)任，就財(cái)產(chǎn)權(quán)利、利益的轉(zhuǎn)移取得的一致同意。
contract(合同)和agreement(協(xié)議)是不是可以互換呢？
合同的成立必須具備幾個(gè)主要因素。它們（要約和承諾構(gòu)成的）協(xié)議、約因、設(shè)立法律關(guān)系的愿望和締約能力四大部分組成。
l.b curzon編著的“a diction of law”提到：“contract generally involves”
1. offer and absolute and unqualified acceptance (要約和絕對(duì)接受)
2. consensus ad idem (意思表示一致， 也叫meeting of minds)
3. intention to create legal relations (建立合同關(guān)系的意愿)
4. genuineness of consent (同意的真實(shí)性)
5. contractual capacity of the parties (合同當(dāng)事人的締約能力)
6. legality of object(標(biāo)的物的合法性)
7. possibility of performance (履行的可能性)
8. certainty of terms(條款的確定性)
9. valuable consideration(等價(jià)有償)
black ’law dictionary" 中解釋道：although often used as synonyms with "contract", agreement is a broader term, e.g. an agreement might lack an essential element of a contact."
“合同任何一方當(dāng)事人不得轉(zhuǎn)讓本合同”英文表述為“neither party hereto may assign this contract”，其中“hereto”表示“to the contract”，選用“neither party to the contract”較少。
3. 同義詞、近義詞、相關(guān)詞的序列
for value received，the undersigned does hereby sell, transfer, assign and set over to ______ all his right, tile and interest in and to a certain contract dated ______, 19____ by and between the undersigned and ______，a copy of which is annexed hereto.
在這里的同義詞和近義詞并列（如sell, transfer, assign and set over，right和 tile and interest），在英文合同里十分普遍。這是出于嚴(yán)謹(jǐn)和杜絕漏洞的考慮，有的也屬于合同用語的固定模式。如：
this agreement is made and entered into by and between party a and party b.句中“made and entered into”和“by and between”兩組分別屬于同義詞和相關(guān)詞并列。
for and in consideration of mutual covenants and agreements contained herein, the parties hereby covenant and agree as follows: 句中“for and in consideration of ”， “covenants and agreements”三組同義司和近義詞并列。
the parties have agreed to vary the management on the terms and subject to the conditions contained herein. 這里的“on the terms”和“subject to the conditions”是一個(gè)意思都表示“依照本協(xié)議的條款規(guī)定”。合同條款的固定模式是“terms and conditions”
再例如： ，
“party a wishes to be released and discharged from agreement as from the effective date”，一句中的“release”和“discharge”意思幾乎相同。
并列的詞還有：
ships and vessels
support and maintenance
licenses and permits
charges, fees, costs and expenses
any and all
any duties, obligations or liabilities
the partners, their heirs, successors and assigns
control and management of the partnership
applicable laws, regulations, decrees, directives, and rules
5. 拉丁詞 ，
在國(guó)外合同中，拉丁詞仍然是很常見：
比例稅率：用pro rate tax rate要比proportional tax rate多
從事慈善性服務(wù)的律師：pro bono lawyer，不怎么用lawyer engaged in charitable legal assistance
委托代理人：多用agent ad litem
contract 與 agreement的有無區(qū)別
在英語中，合同一般稱為contract，協(xié)議一般稱為agreement。
何謂“contract”?
1999年中國(guó)《合同法》第二條對(duì)contract定義為： a contact in this law refers to an agreement establishing, modifying and terminating the civil rights and obligations between subjects of equal footing, that is, between natural persons, legal persons or other organizations”。根據(jù)這一定義，合同平等主體之間設(shè)立的確定民事權(quán)利和義務(wù)的協(xié)議。 ，
steven h. gifts編著的“law dictionary”中將contract 定義為“contract is a promise, or a set of promises, for breach of which the law gives remedy, or the performance of the which the law in some way recognize as a duty.”根據(jù)這一定義，合同是一種承諾，違反承諾可以得到法律救助，某種意義上法律將履行該承諾看做是一種補(bǔ)償。
l.b curzon 在其編撰的字典“a dictionary of law”給contract的定義：“contract is a legally binding agreement”根據(jù)這一定義，合同就是有法律約束力的協(xié)議。
綜合起來，有一個(gè)相同點(diǎn)，就是“contract is an agreement”，即可將合同說成是“an agreement which binds the parties concerned”或者說合同說成是“an agreement which is enforceable by law”， 也可以說：contracts are promises that the law will enforce。 ，
何謂“agreement”? ，
l.b “a consensus of mind, or evidence of such consensus, in spoke or written form, relating to anything done or to be done.”
根據(jù)這一定義，協(xié)議是對(duì)已經(jīng)做或準(zhǔn)備做的相關(guān)事宜，經(jīng)過談判、協(xié)商后〉靡恢亂餳�，诣�諭坊蚴槊嫘問階齔齙腦級(jí)ā?nbsp;
black "law dictionary"有兩個(gè)定義。一個(gè)是：“a concord of understanding and intention between two or more parties with respect to the effect upon their relative rights and duties, of certain past or future facts or performance”根據(jù)這一定義，協(xié)議即雙方或多方京某些過去或?qū)砟承┦聦?shí)的相關(guān)權(quán)利、義務(wù)或相關(guān)權(quán)利、義務(wù)的履行而達(dá)成的一致理解和愿望。
另一個(gè)是：“the consent of two or more persons concurring respecting the transmission of some property, right or benefits, with the view of contacting an obligation, a mutual obligation.”根據(jù)這一定義，協(xié)議即兩個(gè)或多個(gè)當(dāng)事人，為了約定單方責(zé)任或相互責(zé)任，就財(cái)產(chǎn)權(quán)利、利益的轉(zhuǎn)移取得的一致同意。
contract(合同)和agreement(協(xié)議)是不是可以互換呢？