Not very well. Welcome to the FIFTH! YES THE FIFTH! installment of "You Want to Go Home and Rethink Your _________".
The rest of the series:
You Want to Go Home and Rethink Your Superior Race
You Want to Go Home and Rethink Your Chosen One
You Want to Go Home and Rethink Your Redemption Arc
You Want to Go Home and Rethink Your Love Triangle
And onward to the universal language.
This is terribly overused. It seems like every fantasy land or space story has ONE language that EVERYBODY speaks, and there are little to no exceptions. The one guy they need information from right that second or the world will blow up probably doesn't speak the universal language (and they left their translator at home) probably can't speak the common tongue, but he's only included for suspense.
Basically my problem is this: Universal languages are used constantly, and only discarded to build suspense or create drastic misunderstandings and dramatic irony.
So allow me to suggest situations where it's fine to use a universal language, and ways to improve this trope when you do use it.
1. You can have a mostly universal language if the country it originates from is the center of power.
Let's take English, for example. Many countries start teaching their children English from the time they're very young because that is the language spoken by many powerful people who at some time or another controlled a large part of the world (England's former empire, anyone?) and the business that went on in that world.
So if your "universal language" exists because one country or planet has taken control of a lot of what goes on elsewhere, or if one people group has formed an empire, it's fairly justified in it's existence.
2. Not everybody will jump on the bandwagon.
That being said, bear in mind that there are going to be quite a few people groups who either haven't been or refuse to be influenced by this empire, and these people are either not going to speak the language, or speak it very badly. And they're not just going to show up to add suspense. If your characters are going on a quest or leaving their home for any reason whatsoever, they're probably going to run into at least one person who doesn't speak their language. These people could be hostile or friendly, but whatever they are, they exist and should have a place in your story. Oh, and I should point out: JUST BECAUSE THEY'RE NOT A PART OF THE EMPIRE OR ARE FAMILIAR WITH THE COMMON LANGUAGE DOES NOT MEAN THEIR INFERIOR. Different and/or unique people groups are fine, but do not write them as inferior just because they aren't a part of your grand collective.
3. People will still retain something of their original language/culture.
You know how people who don't have English as their first language speak with an accent? THE SAME IS TRUE IN FICTIONAL WORLDS. Unless your characters are part of a controlling society in which nothing but the common language is allowed to be spoken, your various people will have accents and cultural differences. Especially if the language is only spoken because of trade or business. Actually, shoot that. They'll probably have accents anyway. And it's fine! It makes them unique! It shows that the world is big and many different people inhabit it!
4. Don't forget how vast our planet is.
Something people forget when writing about other planets is that they're not the same as a country. NOT. AT. ALL. Countries can have one people group and only one or two types of environments, but planets, especially ones capable of sustaining human life, should not have one of either. There should be different countries, governments, races, languages, terrain, environments, animals, and so on and so forth. Remember, our planet is HUGE, and VARIED. Making other planets one-shot wonders counts as cheating in my head.
5. Try having translators instead of one language.
Instead of having everyone speak the same language, have a computer that can translate most known languages or a person on board your ship or part of your team who can understand a bunch of languages. For example, in Star Trek they use universal translators, a handheld device which can translate alien languages into the language of the user.
Having translators instead can actually eliminate the need for a universal language, but to make them realistic they shouldn't be able to translate EVERY language. There are going to be dialects or languages completely unknown to the creators of the translator, so unless it figures out languages itself (in which case humanity beware because technology is about to take over), you'll still have the same problem you get in point 2.
So there you go! How to use a universal language so it doesn't sound like there's no variety in your story.