时态－－主将从现 主句一般将来时， 从句一般现在时
Revision
if条件状语从句结构及时态
1. 如果主句是一般将来时，从句则用一般现在时。
If it rains（从句）， I will stay at home. I’ll go with you if you don’t want to go alone（从句）.
4.如果你去， 我也去。 If you go,I will go.
5.如果明天下雨，请带雨衣。 raincoat excellent
Please take a raincoat if it rains.
practice
If you are free this weekend, what will you do ?
If she w__a_lk__s to school, she _w_i_ll__ _b_e_late.
1) 条件状语从句通常由if或 unless(=if not)引导，从句中常用 一般时代替将来时，即if或unless 后的句子谓语用一般现在时。但 是，主句则通常用将来时，情态 动词或祈使句。
listen to teachers carefully. do homework by yourself.
• If you want to get good marks, • don’t _c_o_p_y_y_ou_r_h_o_m. ework.
talk in the class cheat in the exams
you’ll be very tired in class your parents will be sad. you won’t get good grades.
your eyes will be poor
Lead-in
She is going to walk to school.
She will be late.
If I become sad, I will cry.
She is doing her She gets good grades. homework.
If you are hard-working, you will get goodr games on weekdays ,
If you have enough pocket money, what will you buy?
• If I have enough pocket money, • I ____________________.
If you invite foreigners to China, where will you go?
• e.g. If you work hard, you’ll pass the exam easily.
• = Work hard, and you’ll pass the exam easily.
• If you don’t work hard, you’ll fall behind others.
2.如果主句含有must, may, can 等情态动词，从句也要用
一般现在时。
If you drive too fast, you may have an accident. You must stop if the traffic is red.
3. 如果主句是祈使句，从句同样要用一般现在时。
Don’t go and play football if you don’t finish your homework.
Revision
Adverbial Clause of Condition if 引导的条件状语从句
-----------复习课
If you are happy, what will you do?
If I am happy, I will smile.
If you become sad, what will you do?
sleep
If I am free ,… watch TV
play computer games
If you want to get good marks, do what? Don’t do what?
• If you want to get good marks, _s_tu_d_y_h_a_rd___.
• = Work hard, or you’ll fall behind
others.
very good
（2）用介词with, without的替代形 式：
e.g. If there is no water, the fish may die.
= Fish may die without water.
• I will go to _________,
• if I invite foreigners to China.
Mount Tai
West lake
Hainan
• If 条件句的替代形式： • （1）祈使句 + and/or + 陈述句（
谓语动词通常用将来时态）。其中 ，and表示句意顺承；or表示转折 ，意为“否则”。
Please call me if he comes next Sunday.
If 引导条状语从句时，从句中用一般现在时代替 一般将来时。 1. If hego_e_s____(go) to the movies,he won’t finish his work. 2. If I b_e_c_o_m__e__(become) a doctor,I can help others. 3. If we _h_a_v_e___(have )time, we will go to the park tomorrow.
If you help me, I’ll finish my task on time.
=With your help, I’ll finish my task on time.
Activity 1 Rewrite the sentences with if: