Auxiliary Verbsافعال کمکی
برای منفی و سوالی کردن جملات از افعال کمکی استفاده می‌کنیم. برای منفی کردن جملات کلمه "not" را بعد از فعل کمکی قرار می‌دهیم.
They do not / don't live in London.
آنها در لندن زندگی نمی‌کنند.
You should not / shouldn't smoke here.
نباید اینجا سیگار بکشی.
برای سوالی کردن جملات فعل کمکی را قبل از فاعل قرار می دهیم.
Does he have a car?
آیا او ماشین دارد؟
Can I open the window?
(آیا) می‌توانم پنجره را باز کنم؟
افعال کمکی "does" ،"do" و "did" را فقط در جملات منفی و سوالی استفاده می‌کنیم. این افعال کمکی معمولا در جملات خبری مثبت استفاده نمی‌شوند.
مشتقات فعل "to be"، یعنی "are" ،"is" ،"am" در زمان Present Simple و "was" و "were" در زمان Past Simple هم نقش فعل اصلی و هم نقش فعل کمکی را بازی می‌کنند.
She is not / isn't my classmate.
او هم‌کلاسی من نیست.
Were you at home last night?
آیا تو دیشب خانه بودی؟
برخی افعال کمکی مانند "may" ،"should" ،"can" و ... معنی جلمه را نیز کمی تغییر می‌دهند.
It may rain tonight. (possibility)
امشب ممکن است باران ببارد.
Can he play the piano? (ability)
آیا می‌تواند پیانو بزند؟
You shouldn’t eat a lot at night. (Advice)
شب‌ها نباید زیاد غذا بخوری.
Exercises
Complete the sentences with the correct auxiliary verb: am, is, are, was, were, do, does, can, should, may.
1.____ you at school yesterday?
Were you at school yesterday?
2.She ____ speak German well. (not able)
She can't / cannot speak German well.
3.____ they like football?
Do they like football?
4.I ____ not feel well today.
I do not feel well today.
5.We ____ go to the park tomorrow. (possibility)
We may go to the park tomorrow.
6.____ he have a pet?
Does he have a pet?
7.You ____ eat more vegetables. (advice)
You should eat more vegetables.
8.They ____ at home now.
They are / aren't / are not at home now.
9.I ____ sorry for being late.
I am sorry for being late.
10.You ____ use your phone in class. (not allowed)
You can't / cannot use your phone in class.