วันพุธที่ 17 ธันวาคม พ.ศ. 2551

must (not), (don't) have to

In the affirmative have to / must both express the idea of obligation.(It is necessary that you do something.) However, must is only used in the present, and is never used after 'will' or 'may.'
-I must / have to get up early because I start work at 8 a.m.
-I will must / have to leave work early if the snowstorm continues.
In the negative only the verb have to (do/does not have to) expresses the idea of obligation:(It is not necessary that you do something.)
-You don't have to pay for children. They can come in for free.
In the negative must (must not / mustn't) is similar to an imperative: Do not do something:
-You mustn't smoke in the corridors. (= Don't smoke in the corridors.)

วันพุธที่ 3 ธันวาคม พ.ศ. 2551

New Yahoo Directory

Arts & Humanities : Photography, History, Literature, Performing Arts…
Business & Economy : Products, Shopping, B2B, Finance, Jobs…
Computers & Internet : Internet, WWW, Software, Games…
Education : College and University, K-12…
Entertainment : Movies, Actors, Humor, Music, TV…
Government : Elections, Military, Law, Taxes…
Health : Diseases, Drugs, Fitness, Medicine, Hospitals, Medical Centers...
News & Media : Newspapers, TV, Radio…
Recreation & Sports : Sports, Travel, Autos, Outdoors…
Reference : Phone Numbers, Dictionaries, Quotations…
Regional : Countries, U.S. States, Local…
Science : Animals, Astronomy, Biology, Engineering…
Social Science : Languages, Archaeology, Psychology…
Society & Culture : People, Environment, Religion, Home & Garden, Food…