Arabic, the official language
To communicate with the population during your trip to Jordan, you must have knowledge of Arabic, which is the country's official language. If you have no foundation in Arabic before you leave, you will find it difficult to remember more than a few simple pleasantries. To hold a long, in-depth conversation, it might be a lot more complicated. Already knowing how to say "hello, goodbye and thank you", will already make the people you are speaking to delighted with your effort. Don't worry about faults and other pronunciation errors, the Jordanians like to see a foreigner say a few words to them in Arabic and relationships can only be more warming as result.
Advice on pronunciation
As well as knowing the vocabulary, you will need to have an understanding of the pronunciation. Which of the two is the hardest? It's hard to say, both are complicated. So to speak Arabic as well as the Jordanians, you are going to have to respect certain rules.
Firstly, in Arabic you particularly need to insist on letters that are doubled. If a word has an apostrophe " ' ", you must come to a stop, like a contraction of the glottis. The following pronunciation rules are also essential for you to be aware of. The "e" is pronounced as "é" as in French. The "gh" is pronounced as a "r" as in French. The "h" is the same as "h" in English. The "kh" is the same as "la jota" in Spanish The "q" is a sort of mix between the "k" and the "g" and should come from the back of the throat. The "sh" is pronounced like the "ch" and the "th" as in English, such as the word "this". The "u" is pronounced like "ou", the "w" like "whisky" and not like "wagon". Finally the "y" should be pronounced as it is in "yoyo"
Speaking in English
After having greeted someone in Arabic and you wish to carry on with the conversation, you have English to help you. Not everyone in the country speaks it but you will always easily be able to find someone who can help you. All Jordanians working directly or indirectly with tourists can speak English. If you also struggle with English, consider taking a dictionary with you.