This is the 3569th most frequent Arabic word.
يعرفون
"They know."
Here, 'يعرفون' is used to indicate the plural present tense of 'to know' (they know). It expresses awareness or understanding of a fact.
يعرفون أنها الحقيقة.
They know that it is the truth.
In this interrogative sentence, 'يعرفون' functions as the verb 'to know' asking about the ability or knowledge of doing something.
هل يعرفون كيفية التحدث باللغة الإسبانية؟
Do they know how to speak Spanish?
'يعرفون' here denotes the plural present tense understanding or familiarity with someone (me in this case).