acquaintance = "knowledge of" or "familiarity"

Dear teachers,

Would you be so kind to help me to make the proper choice of the interpretation of the words in bold in the following sentences?

Acquaintance in the mother tongue with the plot, characters, atmosphere, and general significance of a story may well be an excellent preliminary step to the study of that story in the new language.

acquaintance = knowledge of; familiarity

He parades one’s knowledge of English language. or
acquaintance = familiarity, as in

He has some familiarity with statistics.

Thanks for your efforts.

Regards,

V

Well, I'm not a teacher, but I think in the sentence "Acquaintance in the mother tongue with the plot..." the word acquitance means "familiarity".