Lao language

The official language of the Lao People's Democratic Replublic is "Lao". The language of the ethnic majority. Lao is basically monosyllabic, tonal language. It has 6 tones, 33 consonants and 28 vowels. All dialects of Lao are members of the Tai half of the Tai-Kadai family of languages and are closely related to the languages spoken in Thailand, northeast Burma or Myanmar - (Shan state), Yunnan (SipSong Phan Na)- Guangxi province, China and Vietnam (SipSong Chu Tai).

Standard Lao is indeed close enough to standard Thai (Thailand), for native speakers, the two are mutually intelligible. Even closer to standard Lao are Thailand's northern and north-eastern Thai dialects.
North-eastern Thailand (also called Isan is virtually 100% Lao in vocabulary and intonation; in fact there are more Lao speakers in Thailand (around 20 million native Lao, speak dialects which are closer to Vientiane than Bangkok) than in Laos (around 5.2 millions people).

Standard Lao - Phasa Lao - as spoken by the people in the capital Vientiane, is the official language. It is increasingly known and used among other ethnic groups in different part in Laos, though many of them still prefer to use their own dialets, switching to standard Lao when in school, public service offices or when encounter officials, social workers and the like from the towns.

The most common greeting is Sabaidee, it means 'good morning/good afternoon/good evening' in Lao. But traditionally, the "Nop/Wai" is widely used thoughout the country. A gracious, prayer-like guesture in which both hands are lightly clapsed together at chest height, with a simple word "sabaidee". If you are leaving, you can also do the "Nop" with a parting word "Lah-korn", that means 'Goodbye'. Most of the time you'll receive a kindly response "Sok Dee (Good Luck) from the person who stays behind.