We often find our selves in situations there both parties are using a second language and not mother tongue in a business situation. That is actually a very positive and equal situation. No one is taking advantage of being superior in speaking and playing around with words and expressions that confuses.
Focus on communication as a business tool
Create your own dictionary with the key vocabulary, words and abbreviations that is important in your sector and for your specific goods and services. Practice to do your presentation and describe the offer before you are in the real situation and stick to your "manuscript".
Don´t be afraid to ask for clarification and explanation if you don´t get what your partner, customer or supplier tells you. It is good for both parties to sort things out during the meeting instead of breaking up deals afterwards.
With all the automatic tools for translation of text and voice today you might also be able to find a tool or two that fits your purpose and type of dialogue. Keep your eyes open and ask colleagues, friends and even strangers travelling what they use and what they can recommend.
Key point in our message - don´t let the language stop you from doing business - find a way to communicate, build a relation, create trust and mutual understanding - and just close the deal!