Is a "To Do List" familiar to other countries?
Solution 1:
As far as the U.S., I think it's safe to say that it's almost a universally understood phrase.
Solution 2:
It's fine for the UK.
I'd definitely hyphenate it, though: "to-do list".
Solution 3:
Do not worry. I am not a native speaker, but the first time I saw this expression I immediately understood what it meant and adopted it. This sort of construction is one of the beauties of the English language when compared with more cumbersome languages. (Liste des choses à faire is word for word list of things to do and the correct translation of to-do list into French.)
Solution 4:
I'm not sure that one should equate a to-do list with a list of tasks; consider this list:
- Mow lawn.
- Pick up dry cleaning.
- See movie.
- Go bar-hopping
There are four things to be done (or four to-do's, if you like), but only two tasks.