An observation by my pupil about verbs with a perfect in -u.

He is in 8th grade in my country's system (lower secondary level, 14y.o.). I introduced them to the perfect tense a few weeks ago.

His observation is as follows (paraphrased by me):

If a second-conjugation or third-conjugation verb has a root that has the syllable structure CVC, it will usually have a perfect stem in u.

I lauded him and then told him that is exactly the kind of observation that is often needed in linguistics, but that in Latin, this particular observation may turn out to not be the case.

He was then thinking about researching this question for a project next year and doing some statistics.

What a good lad!

But my question now for you is, do we know about correlations between phonotactial make-up of a verb and how it makes its perfect stem?