By solely speaking English, you will get by in Malta. If you plan on spending an extended amount of time on the island you should reach a high level of English as it will make your Maltese experience all the more enjoyable.
English is spoken by 88% of Malta's population. It is an obligatory subject in primary school and is the language in which classes at secondary and higher education are taught in. Formal documentation and government business is carried out in English too. You will therefore need to have at least a basic knowledge of English if you plan to do business in Malta (e.g. buying property).
Language tourism is very important to Malta. English language schools are present in every major town. Class sizes vary but do not tend to exceed 15 pupils, with prices depending on the course and time of year. Peak season courses (summer time) are the most expensive. On average, an intensive one week course with 20 lessons per week should cost around 100 Euros (2009). The University of Malta also offers free language courses for students.
If you do not have the time or money for regular lessons, home learning packages and pronunciation CDs can be a good starting point. Watching films in English is also very effective. You can watch them with or without subtitles to improve your reading and listening skills.