(1)它(thing or animal spoken of)(指提及的事物或动物)：I can't find my watch;have you seen～? 我的手表找不到了，你看见了吗? Don't go near the dog because～often bites people. 不要靠近那只狗，因为它常咬人。

(2)他(指婴儿、小孩)(referring to a baby or child，whose sex is not known or not important)：I picked up the baby because～was crying. 我把婴儿抱了起来，因为他在哭。 A child is often frightened when～first goes to school. 小孩第一次上学时常感到害怕。

(3)(指事、物、人)(referring to the thing，event，or person in question)：You have saved my life，I shall never forget～. 你救了我的命，我将永世不忘。I～says，“Keep to the right.” 上面写着 “靠右边行走”。 Who's that? Oh，～'s my friend Peter. 那是谁?噢，是我的朋友彼得。

(4)(表示时间、天气、自然环境、距离等)(used mainly as the subject of the verb 'be' to make statements about time，weather ，circumstances or distance)：I～'s five past nine. 现在是9点5分。I～is the third of May. 今天是5月3日。I～'s damp and cold. I think it's going to rain. 天气又潮又冷，我想要下雨了。I～was very quiet in the cafe. 咖啡馆里很安静。How far is～from your home to the station? 从你家到车站有多远?

(5)(用作先行主语或宾语)(as anticipatory subject or object)：I～'s essential to book in advance/for the papers to be ready before Thursday. 事先订票/星期四以前把文件准备好很有必要。Is～true that she is ill? 她病了是真的吗? I～wasn't very clear what she meant. 她的意思不十分清楚。 I～'s no use/no good trying to explain — I'm not interested. 解释也没有用，我不感兴趣。I～'s a waste of time your talking to him. 你跟他说是浪费时间。I find～difficult to talk/talking to you about anything serious. 我觉得很难同你谈任何严肃的事。 I think～important that we should keep calm. 我认为我们保持冷静是必要的。

(6)(用于强调)(used to emphasize one part of a sentence)：I～was Mrs Smith who came on Tuesday. 星期二来的是史密斯夫人。I～was on Tuesday that Mrs Smith came. 史密斯夫人来的那天是星期二。this/that is～ 1)这/那正是所需要的; 2)原因就在于此; 3)这就是结局;

→its pron 它的;it′self pron