現(xiàn)在一般時(shí)態(tài)知識大全
一、 定義與講解
一般現(xiàn)在時(shí):表示經(jīng)常性的事情,經(jīng)常性的動作或一般性事實(shí)。
時(shí)間狀語:often 經(jīng)常,usually通常,always 總是,every每個(gè),sometimes 有時(shí),at …在幾點(diǎn)鐘
只有在第三人稱單數(shù)用動詞的“三單變化”,其他用動詞的原形。
三單變化:1.多數(shù)在動詞后+s play — plays like — likes
(1)直接在動詞詞尾加-s.
ask---asks work---works get---gets stay---stays
(2)以字母s, x, ch, sh或o結(jié)尾的動詞,在詞尾直接加-es.
watch---watches wish---wishes fix---fixes do---does
go---goes pass---passes
(3)以“輔音字母加 - y”結(jié)尾的動詞,要先變y為i再加-es.
try---tries study---studies cry---cries fly---flies
2.不規(guī)則變化:
be---- is are have----has
二、一般現(xiàn)在時(shí)用法
1. 表示經(jīng)常性,習(xí)慣性,永久性的動作或存在的狀態(tài).通常與副詞sometimes, often, usually, always, every day (year, month ), once (twice, three times) a day,等時(shí)間狀語連用。
They usually go to school by bike.
I take the medicine three times a day.
She helps her mother once a week.
Mary’s father is a policeman.
There are 50 students in my class.
2. 表示客觀真理,科學(xué)原理,自然現(xiàn)象,等客觀事實(shí)或格言,諺語等。
The sun rises in the east and sets in the west every day.
The man who has never been to the Great Wall is not a real man.
Tomorrow is Tuesday.
三、一般現(xiàn)在時(shí)的句子轉(zhuǎn)換:
(1)當(dāng)句子中有be動詞或情態(tài)動詞時(shí),則把be動詞或情態(tài)動詞(can,could等等)提到主語的前面變成疑問句;在be動詞或情態(tài)動詞后面加not變成否定句.
例:①陳述句:She is a student.
疑問句→ Is she a student?
否定句→ She is not a student.
?、陉愂鼍洌篒 can swim.
疑問句→ Can you swim
否定句→ I can not swim.
?。?) 當(dāng)句子中即沒有be動詞,也沒有情態(tài)動詞時(shí),則在主語前加助動詞do (you,以及復(fù)數(shù)), does(單數(shù)she,he,it)變成問句;在主語后謂語動詞前加助動詞don’t(I,you,以及復(fù)數(shù)), doesn’t(單數(shù)she,he,it)變成否定句,助動詞后的動詞要變成動詞原形。
例:①陳述句:We get up at 7:00 every morning.
疑問句→Do you get up at 7:00 every morning?
否定句→We don’t get up at 7:00 every morning.
?、陉愂鼍洌篠he has a little brother.
疑問句→ Does she have a little brother?
否定句→ She doesn’t have a little brother.