Has anyone ever had to choose either to write the remaining letters of a word in the NEXT line or just jot down below that same line?

Wha
t

In my experience, children up to 9 or something have no problem with this. Just recently, my mother asked my 5 year old in a letter if he would like to come with her to a museum or something and he promptly made an envelope and a letter saying

LIEVE OM
A NEE

which translates to

DEAR GRANDM
A NO

Needless to say, she felt endeared but disappointed. They ended up going to the zoo.

I used to have this issue as a teenager, but now I just picked up the habit of always leaving a right margin. Problem solved.

@cannonau Wait... Up to 9? You mean that problem starts after a certain age (and well after most kids learn to write)?

That's weird, is there an explanation for that?

@ilPinguino heh, I believe I mean just the opposite: they don't mind continuing on the next line when they run out of space in the middle of a word. And I'm saying "up to 9" because I don't have any (recent) experience with older children writing stuff (in a year, I will).