Khmer, also known as Cambodian, belongs to the Mon-Khmer branch of the Austroasiatic language family. It is the second most widely spoken Austroasiatic language after Vietnamese. It is spoken as a first language by 13 million people and as a second language by another 1 million people in Cambodia. Additionally, it is spoken by over 1 million people in Vietnam and another 1 million people in Thailand. There are relatively large expatriot Khmer communities in Canada, China, France, Laos, USA. It is estimated that the total number of Khmer speakers in the world is around 15 million. The history of Khmer is usually divided into three periods:
- Pre-Angkorian Khmer is known only from a few words and phrases in Sanskrit texts.
- Old (Angkorian) Khmer spoken in the Khmer Empire (9-13 centuries) is found in many sources and is relatively well studied.
- Middle Khmer (14-18 centuries) was a period of great linguistic change and borrowing of vocabulary from Thai, Lao, and Vietnamese. It was a period of a gradual transformation of Old Khmer into the modern form of the language.
As the official language of the Kingdom of Cambodia, Khmer is used in the media, government administration, at all levels of education, and in most informal and formal contexts.
Khmer has three main dialects that form a continuum running from north to south:
- Standard Khmer spoken by more educated people in larger cities like Phnom Penh and Siem Reap. It is mutually intelligible with the other dialects, but not all dialects are mutually intelligible among themselves.
- Surin or Northern Khmer spoken in eastern Thailand which is thought to have separated from Standard Khmer in the past few centuries
- Cardamon or Western Khmer spoken in southwestern Cambodia.
The Khmer script is based on a variant of the Brahmi script used to write Sanskrit, Hindi, and other Indo-Aryan languages. The Khmer script has symbols for thirty-three consonants, twenty-four dependent vowels, twelve independent vowels, and several diacritic symbols. It is a syllabic alphabet in which each consonant has two forms, one with an inherent vowel /a/ (first series) and one with an inherent vowel /o/ (second series). Vowels are indicated by using either separate letters or diacritics written above, below, in front of, after, or around the consonants. The pronunciation of the vowels depends on whether a consonant they are attached to belongs to the first or the second series. All consonants have a subscript form that is used to write the second consonant of a cluster. There are no spaces between words in Khmer. Spaces are used to indicate the end of a clause or sentence. Although some efforts have been made to standardize Khmer spelling, there are inconsistencies in the spelling of many words. In addition, the romanization of Khmer is often done on an ad hoc basis. The International Phonetic Alphabet is sometimes used to transcribe Khmer, based either on their pronunciation or on their Khmer spelling. Since pronunciation can vary from one dialect to another, the resulting transcriptions may be quite misleading.