Dont worry, you will do fine. Everyone in s'pore speaks english, worry more about the length of your hair, and shave if you have a full beard (Does not apply to your girlfriend

Malaysia is a bit different, depending on where you are traveling to.KL,Penang,JB are all very touristy, so no prob there. The Malay's living in smaller villages do not always speak english but they will do their utmost to understand and make themselves understood. A hand book is good and easy to get your head round as they use the letter pronounciation.
selamat pagi-good morning
selamat tengahari-good afternoon
selamat malam-good night
trema kaseh-thank you
sama sama-youre welcome
satu-1. dua-2. tiga-3. empat-4. lima-5. enam-6. tugu-7.lapan-8. sembilan-9. sapulu-10. sebelass-11. duabelass-12. Use same single number up to enambelass-19, then it becomes duapolo-20. duapolo satu-21 doapolodua-22....
tigapolo-30 empatpolo-40
The best thing is..booze is the same by name! And if in KL, the guiness is good. There is a huge factory on your way in from the airport..May account for the large Irish comunity there
If you are traveling over to Sarawak, you may well consider another hand book, as malay spoken there is a different dilect (Indionesian influanced) Bahasa malay & Kebansahan malay. If you are a H.H.H. They do a run on the last Friday of every month in Kuching. Have fun