The meaning of the verb is properly, to know, especially through personal experience (first-hand acquaintance).
When read in context the meaning is clear.
Mary's question to Gabriel is how is she going to have the baby when she knows she and Joseph haven't engaged in sexual intimacy.
That can be the only meaning of her question.
Does she know Joseph? Yes. Have they met before? Yes. So it isn't referring to an acquaintance meaning. This leaves only the sexual meaning of the term.
Gabriel explains to her how this will happen in 1:35.
Likewise Joseph, did not "know" Mary until after Jesus was born.
Same questions about Joseph. He knew Mary, they had met, talked, etc. So this only leaves the sexual meaning of the term.
In modern day English we use similar terms for sex. Have you intimate knowledge of him/her?
Again, understanding the Greek and the context of the passages and subsequent ones where Jesus' family is noted can only lead to one understanding.
Joseph and Mary, after Jesus was born, consummated their marriage as any normal married couple would. There is no contradiction of the requirement Jesus be born of a virgin. There was no requirement of Mary remaining a virgin.
Please cite the scripture that states that Mary and Joseph consummated their marriage, I can’t seem to find it.
Thanks,
Love,
O2