This is the 12th most frequent Arabic word.
كان
"Was" or "to be" (past tense).
Here, 'كان' is used to express past-tense of the verb 'to be', indicating the state of the weather in the past.
كان الجو حاراً اليوم.
It was hot today.
In this sentence, 'كان' is used in a conditional clause to describe a hypothetical situation in the past.
لو كان لدي وقت لفعلت ذلك.
If I had time, I would have done it.
In this example, 'كان' is used as part of a question to ask about someone's state or location in the past.