be acquainted with something,be familiar with something,
字典對這倆詞的解釋：
acquainted,文,正式,用法.熟知（用的 familiar）,讀過,看到過,經歷體驗過.
familiar,熟知
註意,這倆詞後面接的都是with something,
這倆次,意義用法相似,但是,acquainted 比較正式,並且意義包涵familiar的意義.正式文體中,無論熟悉,讀到過,看到過,經歷過,略知壹二,都可以用這個詞.
2.
be acquainted with somebody,與be familiar with somebody
意義差異很大了
acquainted,並非親密朋友,但是見過幾面
familiar,指人在行為上,很不正式的,甚至令人不快的
You seem to be on very familiar terms with your tutor.
妳似乎和妳的導師混的挺熟啊.