Some insecure men shrink when they see a beautiful woman walk in; hesitating as though they were going to be rejected as if they were asking for a date. Do not give away your sales because of race or color thinking your co-worker should get the sale because they speak the same language or are of the same color.
What you can do if you do not speak their language or cannot understand them is ask your co-worker to help you translate without giving up the sale. If you are sure the sale is small in nature and would be a waste of your time, by all means turn that customer over to someone who can speak their language and go to the next customer.
Are you shy of the executive types? When you see customers like that do your best to get to them quickly. Keep in mind that these executive types are mere human beings that have the same faults, weaknesses, worries and fears that are shared by most people. Just picture them as they really are, regular folks, not what they appear to be and the mental threat instantly disappears. When you are selling this should give you a hint when someone puts on an act of being superior or arrogant. Customers who seem intimidating are sometimes the biggest spenders.