Language/Standard-arabic/Grammar/How-to-Use-Be

The Arabic verb “to be” is كانَ (kāna)

The discharges of the verb be: present tense

• “I am” = أكونُ (akūnu) / exp  : I am beautiful انا جميل
• “you (male, single.) are” = تَكونُ (takūnu) / exp  : you are beautiful انت جميل
• “you (female, single.) are” = تَكونينَ (takūnīna) / exp  : you are beautiful انت جميلة
• “he is” = يَكونُ (yakūnu) / exp  : he is beautiful هو جميل
• “she is” = تَكونُ (takūnu) / exp  : she is beautiful هي جميلة
• “you (dual) are” = تَكوننون (takūnani) / exp  : you are beautiful انتما جميلان
• “they (m, dual) are” = يَكونانِ (yakūnāni) / exp  : you are beautiful هما جميلان
• “they (f, dual) are” = تَكونانِ (takūnāni) / exp  : they are beautiful انتما جميلان
• “we are” = نَكونُ (nakūnu) / exp  : we are beautiful نحن جميلون
• “you (m, pl.) are” = تَكونونَ (takūnūna) / exp  : you are beautiful انتم جميلون
• “you (f, pl.) are” = تَكُنَّ (takunna) / exp  : you are beautiful هن جميلات
• “they (m) are” = يَكونونَ (yakūnūna) / exp  : they are beautiful هم جميلون
• “they (f) are” = يَكُنَّ (yakunna) / exp  : they are beautiful هن جميلات

The discharges of the verb be;

• “I was” = كُنتُ (kuntu) / I was beautiful انا كنت جميل
• “you (m, sing.) were” = كُنتَ (kunta) / you was beautiful انت كنت جميل
• “you (f, sing.) were” = كُنتِ (kunti) / you was beautiful انت كنت جميلة
• “he was” = كانَ (kāna) / he was beautiful هو كان جميل
• “she was” = كانًت (kānat) / she was beautiful هي كانت جميلة
• “you (dual) were” = كُنتُما (kuntumā) / you were beautiful انتما كنتما جميلتان
• “they (m, dual) were” = كنتا (kanāta) / they were beautiful هما كنا جميلون
• “they (f, dual) were” = كنتا (kanta) / they were beautiful هما كنتا جميلتان
• “we were” = كُنّا (kunnā) / we were beautiful نحن كنا جميلون
• “you (m, pl.) were” = كُنتُم (kuntum) / you were beautiful انتم كنتم جميلون
• “you (f, pl.) were” = كُنتُنَّ (kuntunna) / you were beautiful انتن كنتن جميلات
• “they (m) were” = كانوا (kānū) / they were beautiful هم كانو جميلون
• “they (f) were” = كُنَّ (kunna) / they were beautiful هن كن جميلات 

As you can see, whenever كان is used in a sentence you must be extra careful in determining the subject and object of the verb, just as with ليس. If you have the ليس business down, you should have no problem with كان.

كان is used to form a number of compound tenses (with horrible names) such as the pluperfect, the future perfect, past future, past habitual and past progressive. Below are some examples.

1. I had studied Arabic.	١. كنتُ درستُ اللغة العربية.
2. Samir had studied Arabic.	٢. كان سمير (قد) درس اللغة العربية.
3. We were going to go to the Middle East.	٣. كنّا سنذهب الى الشرق الاوسط.
4. The professors will have killed their lazy students.	٤. يكون الاستاذة (قد) قتلوا طلابهم الكسالى.
5. Samir used to visit his relatives in Jordan every year.	٥. كان سمير يزور اقاربه في الاردن كل سنة
6. Samir was sitting on the chair drinking tea when the policeman entered and arrested him and he was taken to jail where he died under mysterious circumstances.	٦. كان سمير يجلس على الكرسي يشرب الشاي عندما دخل الشرطي واعتقله وأُخذ الى السجن حيث مات تحت ظروف غامضة