Do you want to hear some bad news? English speakers are among the least popular tourists anywhere in the world. And if you're reading this and go on holiday it means you fall into that category. It's not that people in other countries don't appreciate the boost to their economy from tourist spending. It's just that English speakers often seem to expect that everyone else speaks English.
It's not easy to learn another tongue. Some of us pick them up a little easier than others - it's often called "having an ear for languages". But you should ideally always have a few words of the language of the place you're going to - even if it's just "Parlez-vous Anglais?".
That's the other thing - most of us have done some language learning at school. French, Spanish, maybe German or Italian, often it's enough to allow us to order a coffee or get a taxi to the train station. The more esoteric our destination, the less likely that is. You probably don't know the Croatian for "I would like a medium-rare steak, please." So there are some survival tips it helps to know.
Be Polite. It Helps.
The locals in any place you go to on holiday are people just like you. Yes, there is a trope that French people are rude. But one has to wonder how much of that is from their reaction to English speakers asking them "Where is the toilet, s'il vous plait?". Usually at a very high volume, too. People will be more patient if you are obviously apologetic and grateful when appropriate.
Gestures Can Get You Everywhere
Imagine that someone - we'll say they're Belgian, to pick a nationality at random - walked up to you, said "Balloons?" and looked expectantly at you. You'd be right to feel a little perplexed. If you don't know how to ask a question, don't just take one word out of context and repeat it. Instead, realize how useful gestures can be. If in India, you can get from Delhi to Manali by train just by knowing where to point on a map.
Key Words Can Help You Out
As noted, learning a full language in preparation for a holiday is nearly impossible. Especially if it’s Chinese or one with a similarly unfamiliar alphabet. A few essential sentences for emergencies will be useful. Also useful is learning single key words. If you know how to say "thank you," people will be more receptive. "Sorry" is also helpful, as is "excuse me." If you're eating in a restaurant, "delicious" is also worth knowing.
Technology Is Your Friend
If you take an entire article from an Icelandic newspaper and feed it through Google Translate, it will read like gibberish. However, for single words and key phrases, it is a very useful tool. For times when you have no network connection, you can download target language dictionaries, too. So you may not be able to analyze the finer points of a play you just watched, but you can find out how to say "pharmacy" - which is much more useful.
The bottom line is that no-one will expect fluency from you if you're just in the country on holiday. They can, however, reasonably expect you to try and to be polite. People are used to English-speaking tourists expecting them to understand English. Taking the effort to speak to them in their language will see them responding much more warmly.