You can buy a SIM card in every shop selling mobile phones, or showing their network's brands. The standard price is no higher than 75000 dong, but foreigners are often charged 100000 dong. Prepaid account charges vary from 1700-2500 dong per minute. Roaming onto Vietnam's GSM networks are possible with foreign mobile phones, subject to agreements between operators.
The official language of Vietnam is Vietnamese, a tonal Mon–Khmer language which is spoken by the majority of the population. Different from Western languages, tourists may be surprised to learn that the basic grammar is pretty simple. People have a basic grasp of English, but proficiency is generally poor. Most hotel and airline staff will know enough English to communicate. Directional signs are generally bilingual in both Vietnamese and English.
Internet access is available in all but the most remote towns. Internet cafes are available in most tourist spots and rates are fairly cheap, ranging from 2000-10000 dong per hour. Connection speeds are high, especially in the big cities. Many hotels and restaurants provide free Wi-Fi or terminals for their guests.