How do you avoid "tourist traps" when traveling to a country where you do not speak the language?

First, it's not a binary you're-in-the-tourist-zone-or-you're-not kind of thing. There's a spectrum. Second, often the "real" is only 20 feet from the "for the tourists". Something as simple as sitting down in a park and watching people go by can tell you a lot.

I like to talk to the hotel clerks. On my most recent trip (to Venice), the woman who was at the front desk most days actually lived in Venice (unusual) and she showed us a simple route to St. Marks from the hotel (that we would never have found and that was crowd-free till you came out under the clock tower) and recommended two specific churches to visit that many people miss but which are absolutely beautiful. She also suggested walking around some less popular areas, and we enjoyed that a lot.

At first it seems that all of Venice is fake, but there is reality there. I was happy to see a bit of it. I believe people who live in a place will be happy to tell you where the real place is.

I am glad that the Lonely Planet and Rough Guide etc exist - for the average tourist to find good places. However those then inevitably become the very tourist traps they were intended to avoid.

I prefer Wikivoyage - it's up to date and because most use the books, the treats on that site are often less visited and still diamonds hidden in the rough.

In addition, always walk off the main streets. It's amazing how much less touristy just one side street away from the main street it becomes, and how the prices drop to reflect this. In addition they're usually appreciative of you doing so, and you'll get great service.

Failing that, find a local, draw a picture or point to your belly if hungry, it'll usually get a laugh and a suggestion :)

In my experience, the biggest factor in overcoming limitations while traveling is time. The longer you are there, the more chance you will have to filter out that which is designed to catch your eye when making snap decisions on how to use your time. If you want a more genuine, in-depth experience, consider staying for longer.

If you can find volunteer work in or near your destination, you will likely find other travelers who have more experience than you and are willing to share. Volunteer work, I've found, is a type of currency, just like time. Also, host country nationals who collaborate with volunteers are often excited to share their country with someone who has devoted some time to their cause or organization.

If you want to volunteer in whatever place you go, an excellent starting place is idealist.org. Some of them charge a fee, while others you can just come and help out at your own expense. There are even some that pay, but they tend to want a multi-month/year commitment.

One of the things you can do is go to restaurants that are popular with the locals. Use Google Translate to find sites that show where locals like to eat. For example, "best restaurants in buenos aires" = "los mejores restaurantes de buenos aires". Search for that in Google and Guiaoleo shows up, which is a Spanish language review site for Buenos Aires restaurants. The top restaurants there will be different than the ones you find on TripAdvisor.

Don’t be intimidated if they don’t have an English menu. Write down the words for fish, chicken, vegetarian, etc., before you go. When you’re ordering, just point at items on the menu.

You have a good chance meeting locals when hitchhiking. I usually go almost blind - no travel guide, no plans, and just ask the drivers. Some of them are really fond of their country/city and like to talk about it. People taking hitchhikers tend to be travellers themselves and often know English, at least in my experience.

In order to avoid the tourist traps, someone in your party needs to speak the language. If that person isn't you, you probably need to take someone along that does.

I'd start by trying to make one or more friends in the hotel I'm staying, who speaks my language and the local language. Or this friend could be a worker in a shop or work area near your hotel. Find out when they're off duty. Then ask them if they'll take you around if you pay for both parties' entertainment. Unless their place of work specifically has a prohibition against "fraternizing," or they have "family" obligations of one sort or another, many will be happy to take you up on this kind of offer. Naturally, they will suggest the thing that most appeals to them, but this will be off the "beaten" (tourist) trap.

There's nothing that's "perfectly" safe, but you will less likely get robbed/mugged/kidnapped by someone that has a steady job at a hotel or restaurant, particularly one catering to foreigners. Just don't do this with someone you've met "off the street" who doesn't have "recommendations" of any kind.

When paying for something I always try to watch and see what local people are paying for the same thing and then pay the same regardless what they ask for. When buying stuff in a shop I always try to get things with a price tag, so they can not decide the price on the spot. I always thought I was safe that way.

Recently I went into a small supermarket in central Budapest with a local and at the cash point my bill was considerably lower than the sum of the prices on the price tags. I enquired about this and was told that the price tags were for tourists, and locals (and their friends) pay less.

I try not to buy anything for the first few days, so I get the feeling what the common ripoffs are in this area, or ask other people what's the catch on some of those offers who seem to be to good to be true.
Lonely planet is a good source for this sort of advice as well.