[vram22]

(Note: I use Python a lot, so sort of biased, maybe ...)

>I want to spare him from significant whitespace for a while

Reasonably smart kids can understand a lot of things if one takes the time to explain it to them a bit, along with the reasons why a particular thing is the way it is.

I'd suggest you try to avoid dumbing things down too much, just because he's a kid. You might be surprised.

Logo (language) could be another option, and is pretty cool for kids (of all ages :) There are free versions available, just google for them or see the Wikipedia page for Logo.

[sdegutis]

It's not about understanding. I'm sure he can understand it just fine. But he's also learning how to use an editor. Throwing in significant whitespace is just going to add frustration.

[vram22]

IMO, that's not such a big deal - understanding what significant whitespace is, if you're prepared to have him deal with significant newlines, as you said. But it's your choice, of course ...