１、构成；使用动词原形，第三人称单数须有变化。
（１）直接加“s”，works takes
（２）以辅音加“y”结尾，变“y”为“i”，再加“es”
carry ――carries
（3）以“o，s，ch，ｓh”结尾的动词加“es”
goes dresses watches brushes
2．功能；
（１）表现在的事实，状态或动作；
eg； Birds fly。
She loves music
Mary‘s parents get up very early
（２）表示习惯动作或职业，常与often，sometimes，usually，always，every week，
seldom，occasionally，frequently等时间副词连用。
eg；I always take a walk after supper。
She writes to me very often
Tom and his girlfriend go out to take apicnic occasionally。
（３）表客观真理，格言警句或事实；
The earth moves round the sun。
The sun rises in the east and sets in west。
Two and twomakes foｍａMMur。
No man but errs。人非圣贤，孰能无过。
（４）表将来；
A． 在由when，after，befors，as，as soon as，although，because，if，even if，in case，till ，until，unless，so long as，where，whatever，wherever等引导的状语从句中用一般现在时表将来发生的动作。（黄金重点，所有考试都不放过它！！！）
例如I`ll tell her when she comes tomorrow
Even if it rains this afternoon，I`ll meet you。
Whatever happens，you should keep cool-headed（不错的句型，背下！！！）
I`ll be right here waiting for you wherever you go。（很感人的句型！）
B．按时间表示将要发生的动作或事件，用一般现在时表达将来时概念。
The play begins at 6；30 this evening。
When does the plane take off？
He leaves for that city next week。
According to the timetable，the express train to Shanghai starts at nine in the morning（按照时刻表，开往上海的特快列车早上7点出发。）