Yah I live in LA and we have tortas all over the place over here. But my family is from Ecuador and for us a torta is a birthday cake. I don't think I've ever used the word emparedado. I just normally use the word sanduche. It's interesting how many different words there are for the same thing.
This has come up many times in the discussion forum. I think most people have agreed "emparedado" is generally not used to mean what people call a sandwich in English speaking countries. You can search to see what others have said. But if you do a google image search for "emparedado" you do see mostly images of what English speakers would call sandwiches.
I've read that emparedado is used in Panama, but I've yet to ask anybody from there about it. I've seen it in print, but I've never heard anybody say it out loud in real life for sandwich (the food). In México, torta, sándwich (sangüich) and occasionally bocadillo. Sándwich is a different type of sandwich than a torta. Torta means different things outside of México.
If it's on sliced bread, sándwich will probably be understood anywhere in the Spanish speaking world. For some reason television and print often use emparedado. Maybe it's archaic. It literally means surrounded/wrapped by walls.
Yes, actually the "contener" (to contain = something that HAS something in its composition or WITHin) is "con (with) + tener (to have)" and the conjugation of "contener" for all the times is the same as for "tener" but only with "con" in front. I found it useful and easy to remember.
I answered, "The sandwich has cheese." which seemed a more natural way to say it in English for me. It accepted it, but said I added an extra space and that it should be "The sandwichhas cheese ." with no space between sandwich and has, and an extra space before the period. I guess I'm not the only one who makes typos.