Sorry about the broad title, but I am a newish Chinese student (just finished HSK1) and there's a concept that continually appears in my classes that I can't grasp.
Basically, there are lots of situations where omitting a word can be done or not (think 我爸爸 VS我的爸爸 for example), or where one can chose between a long or short word (商店 vs just 店).
In many of those cases, my (native) teacher switches between using one option or the other during a dialogue depending on the specific phrase. When asked about it, she can't really explain why one option is better than the other, she just tells me that some version makes the phrase more "balanced" or that it makes it "complete".
My guess is that it has to do with the cadence of the phrase or something, but I am completely clueless about how to really understand this concept, and I don't even know if it has an actual name. How can I learn more about the topic?