A Hundred and One Rules in Arabic Grammar!
85. کانَ& her Sisters (Revisited).
We said earlier thatکانَ & her Sisters are used with equational sentences. However, they can tolerate the use of verbs after them. That verb has to be in the present indicative form, as in:
**کانـَتْ تـَعملُ في مَکتـَبـِها.**
She was working in her office.
If the subject is expressed, it should be placed betweenکانَ & her sisters and the verb.
**کانـَتِ الأستاذةُ تـَعملُ في مَکتـَبـِها.**
The professor was working in her office.
An exception to this rule is when you want to topicalize the subject, and that simply means that you want to emphasize it.
**الأستاذة ُ کانـَتْ تـَعملُ في مَکتـَبـِها.**