"I understand now."
Translation:מובן לי עכשיו.
Interesting that you say "I understand now" is מובן לי עכשיו when I would think it's אני מבין עכשיו. The passive מובן לי עכשיו is awkward meaning "It is understood to me now". Is such a passive expression used in Hebrew. Perhaps this is just one of those things that doesn't have an accurate direct translation and that's why they provided "I understand now "
I think אני מבין עכשיו is better, something sounds not quite right with מובן לי עכשיו - probably the missing subject. But generally speaking זה מובן לי and אני מבין את זה mean pretty much the same thing.
The structure is very common with adjectives, "טוב לי" "רע לי" "חם לי" etc., and the present tense in Hebrew is often treated as an adjective - so this could be where it's coming from.
Funny, I was thinking of this as "Oh, now I got it!" This emphasizes the timing (now), as opposed to the lighting of the bulb over my head. So, I wrote עכשיו מובן לי. And it was marked incorrect! So, first, I'm a bit annoyed, but, second, it's my impression that word order is less significant in Hebrew than it might be in English. So, isn't עכשיו מובן לי the same as מובן לי עכשיו? Except that the first somehow sounds more right than the second?
Not really, but note that the verb is in a passive voice. A literal translation would be "It is understood by me now". If you remove th e לי you are left with "it is understood now". That is OK if people can figure out that it is you who understands now.
Also, like many verbs in the passive voice, this also doubles as an adjective. So if can be translated "it is clear to me now", and then removing the לי leaves you with "it is clear now". Again, if you are saying it, you are probably referring to yourself, so it's fine to omit the לי.