Arabic is the official language in Saudi Arabia but English is widely spoken and is the main language used in business. Among the non-Saudi population, many people speak Urdu, the official language of Pakistan, and other Asian languages such as Farsi and Turkish. In Saudi Arabia, there are differences between the dialects spoken in urban areas and those spoken in rural areas.
It is usual to address people by their first names in business or at home – but it is respectful to prefix the first name with Mr. at early meetings – so you’d say Mr. Mohammed, for instance, and you might be called Mr. Edward if your name is Edward. A “Dr. Ahmed Bin Al-Rahman” would be addressed as “Dr. Ahmed.”
If you are dealing with a government minister, the correct form is ‘Excellency’, and with members of the large royal family – who are often involved in high-level business – ‘Your Highness’ or ‘Your Royal Highness’, depending on the branch of the family. Don’t use slang, or casual language, don’t say anything that would be considered swearing or blasphemous, and refrain from mentioning religion or politics.