When I work with my clients I too face many difficulties in communicating.While few of them tend to show interest in learning new languages like English which i globally used,few may prefer translators.
Communication is very important aspect in order to have better relation which your on site clients.
But what if the clients are of different language than your and deny to learn?
One way could be usage of translators.If you are attending conference calls,or business meetings you can arrange for a translator for your help.
But not all the time you can keep the translators with you,that adds up to the company's expenses.Alternatively, you can train your employees in that foreign language if you are deputing them to the client place.
Whether there are language barriers or not, respect should be maintained between both the parties. If the client does not know English which is a universal language,you may suggest them to undergo training.
Whether they are from different language or they follow different culture, you should always think you are one team, try to consider their ideas at work.This way you are respecting them.
You need to work a bit harder to convince foreign language teams. But its not impossible.