Don’t use slang, abbreviations or ironical phrases if you want to be understood when talking to foreigners
One way to help others understand you better is to avoid ironical phrases. Irony doesn’t travel well from one culture to another and brings confusion, so try not to use it. Also, stay away from slang, which listeners might not understand; it’s better to use formal language.
Lastly, acronyms and abbreviations. They often make sense in your language but others might find them incomprehensible. If you are French you know what TGV stands for but you’ll have to explain “TGV, which means high-speed train” to Americans.
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