every

Từ điển American Heritage Dictionary 4th

eve·ry (ĕvʹrē)adj.
1.
a. Constituting each and all members of a group without exception.
b. Being all possible:
had every chance of winning, but lost.
2. Being each of a specified succession of objects or intervals:
every third seat; every two hours.
3. Being the highest degree or expression of:
showed us every attention; had every hope of succeeding.Idioms:every bit Informal
In all ways; equally:
He is every bit as mean as she is.every now and then/again
From time to time; occasionally.every once in a while
From time to time; occasionally.every other
Each alternate:
She went to visit her aunt every other week.every so often
At intervals; occasionally.every which way Informal
1. In every direction.
2. In complete disorder. [Middle English everi, everich, from Old English ǣfre ǣlc: ǣfre, ever; See aiw- in Indo-European Roots + ǣlc, each; See līk- in Indo-European Roots.] 
Usage Note: Every is representative of a large class of English words and expressions that are singular in form but felt to be plural in sense. The class includes, for example, noun phrases introduced by every, any, and certain uses of some. These expressions invariably take a singular verb; we say Every car has (not have) been tested. Anyone is (not are) liable to fall ill. But when a sentence contains a pronoun that refers to a previous noun phrase introduced by every, grammar and sense pull in different directions. The grammar of these expressions requires a singular pronoun, as in Every car must have its brakes tested, but the meaning often leads people to use the plural pronoun, as in Every car must have their brakes tested. The use of plural pronouns in such cases is common in speech, but it is still widely regarded as incorrect in writing.·The effort to adhere to the grammatical rule causes complications, however. The first is grammatical. When a pronoun refers to a phrase containing every or any that falls within a different independent clause, the pronoun cannot be singular. Thus it is not idiomatic to say Every man left; he took his raincoat with him. Nor can one say No one could be seen, could he? Writers unwilling to use plural forms in these examples must find another way of expressing their meaning, either by rephrasing the sentence so as to get the pronoun into the same clause (as in Every man left, taking his raincoat with him) or by substituting another word for every or any (as in All the men left; they took their raincoats with them).·The second complication is political. When a phrase introduced by every or any refers to a group containing both men and women, what should the gender of the singular pronoun be? This matter is discussed in the Usage Notes at he and they. See Usage Note at all. See Usage Note at any. See Usage Note at each. See Usage Note at either. See Usage Note at he¹. See Usage Note at neither. See Usage Note at none. See Usage Note at they.