Would it be wrong to say “I start to understand....”?

No, it wouldn’t. Without any context, it’s hard to determine what’s intended.

Евгения, you should add that version too))

Улий, I would be grateful if you could explain this difference between I am starting to do smth and I start to do. It makes no sense to me (or I do not feel it) to use continuous with start or begin. You start or you don't start )) Thank you

I’m starting to... значить «я постепенно начинаю...» - “Last night my roommate came home drunk and called his wife a whore. This morning, she gave him black coffee because we had not milk and he called her lazy. I’m starting to understand why her parents dislike him so much.” Значит, все постепенно становится мне яснее (??)

“Now that I’m watching Russian movies, I’m starting to recognize words more and more.”