Quote Originally Posted by grafrich View Post
Маша и сын её, Саша, ходили пешком за покупками, а сейчас сынок устал.
The idea here was just to express this idea:-
'Masha and her son, Sasha, were going shopping on foot, and/but now the young son had become tired.'
So I chose ходили as I thought it would imply that they do this (maybe) every week; an ongoing habit, a tiring, boring routine. Also to express the idea that they were in the middle of their shopping related journey when the other events occurred. I hadnt given any thought as to whether they had finished buying the shopping, or not. Sort of doesnt matter in this context.
Are those good reasons to choose ходили instead of шли?
Ah, then my initial correction was right, you should have used шли as it was an ongoing action at that time. You see, you're right that ходили implies a routine, habit, but only if the action is not happening now or at a time you're speaking of as ходили implies a completed action in that case.

As @Serge_spb mentioned:

Quote Originally Posted by Serge_spb
"Маша и сын её, Саша, ходили пешком за покупками, а сейчас сынок устал." - is absolutely fine sentence, no need for "шли".
They have already done their shopping.
This means that in your sentence they were on their way FROM shopping and not on their way to "shopping", as you wanted to say.

That's the difference.

Quote Originally Posted by grafrich
I don't know why I didn't realise that I hadn't made it clear that the shop girl could neither see, nor be seen, due to being under the counter and hidden from view. It's so obvious now. Duh. I did write 'А внизу, под прилавком, Алина была невидимо.' later on, but that is a long way after the doorbell rining, I guess I should have put it in earlier.
I think you tried to do that, but failed due to your yet limited knowledge. No worries, you'll nail these kind of things soon enough and we'll be happy to help you on your way.

One thing to note, in Russian невидимый usually means invisible in a sense of not being seen from any angle, in plain sight etc... Special forces kind of invisibility, which is not possible as of now as far as we know. If someone or something can't be seen because they're covered from view by something, then we usually say:

Её/его/их etc не было видно