This is a sentence I wrote on WeChat to another teacher at Nankai University:
But I'm not a student. I'm a teacher at Nankai University.
(Kěshì wǒ bùshì yīgè xuéshēng. Wǒ shì Nánkāi Dàxué de jiàoshī.)
Question: Is it overly formal to say 南开大学 instead of its abbreviation 南大 to people at 南开大学?
I asked some Chinese friends, but I didn't get a precise response. They pointed out that 南大 is often used as an abbreviation for 南京大学 (Nánjīng Dàxué) "Nanjing University" (nowhere near Nankai University, in Tianjin), but when two people are actually at 南开大学, there's not much of a risk of confusion.