Dialects: Dialects are sometimes quite marked. Notable variations are found in speakers from Phnom Penh (which is the capital city), the rural Battambang area, the areas of Northeast Thailand adjacent to Cambodia such as Surin province, the Cardamom Mountains, and in southern Vietnam.[4] The dialects form a continuum running roughly north to south. The speech of Phnom Penh, considered the standard, is mutually intelligible with the others but a Khmer Krom speaker from Vietnam, for instance, may have great difficulty communicating with a Khmer native to Sisaket Province in Thailand. Northern Khmer, the dialect spoken in Thailand, is referred to in Khmer as Khmer Surin and, although it only began divergence from standard Khmer within the last 200 years, is considered by some linguists to be a separate language. This is due to its distinct accent influenced by the surrounding tonal language, Thai, lexical differences and its phonemic differences in both vowels and distribution of consonants. Final "r", which has become silent in other dialects of Khmer, is pronounced in Northern Khmer. Western Khmer, also called Cardamom Khmer, spoken by a small, isolated population in the Cardamom mountain range extending from Cambodia into Thailand, although little studied, is unique in that it maintains a definite system of vocal register that has all but disappeared in other dialects of modern Khmer.[4] A notable characteristic of Phnom Penh casual speech is merging or complete elision of syllables, considered by speakers from other regions as a "relaxed" pronunciation. For instance, "Phnom Penh" will sometimes be shortened to "m'Penh". Another characteristic of Phnom Penh speech is observed in words with an "r" either as an initial consonant or as the second member of a consonant cluster (as in the English word "bread"). The "r", trilled or flapped in other dialects, is either pronounced as an uvular trill (similar to French) or not pronounced at all. This alters the quality of any preceding consonant causing a harder, more emphasized pronunciation. Another unique result is that the syllable is spoken with a low-rising or "dipping" tone much like the "h?i" tone in Vietnamese. For example, some people pronounce /tr?j/ (meaning "fish") as /t?j/, the "r" is dropped and the vowel begins by dipping much lower in tone than standard speech and then rises, effectively doubling its length. Another example is the word /ri?n/ ("study, learn"). It is pronounced /?i?n/, with the "uvular r" and the same intonation described above.[15] Social registers Khmer employs a system of registers in which the speaker must always be conscious of the social status of the person spoken to. The different registers, which include those used for common speech, polite speech, speaking to or about royals and speaking to or about monks, employ alternate verbs, names of body parts and pronouns. This results in what appears to foreigners as separate languages and, in fact, isolated villagers often are unsure how to speak with royals and royals raised completely within the court do not feel comfortable speaking the common register. Another result is that the pronominal system is complex and full of honorific variations. As an example, the word for "to eat" used between intimates or in reference to animals is /si?/. Used in polite reference to commoners, it's /?am/. When used of those of higher social status, it's /pisa/ or /t?tu?l ti?n/. For monks the word is /c?an/ and for royals, /saoj/[2].
Writing system
Main article: Khmer script Khmer is written with the Khmer script, an abugida developed from the Pallava script of India before the 7th century.[16] The Khmer script is similar in appearance and usage to both Thai and Lao, which were based on the Khmer system, and is distantly related to the Burmese script. [16] Khmer numerals, which were inherited from Indian numerals, are used more widely than Hindu-Arabic numerals. The Khmer script is also used within Cambodia to transcribe hill tribe languages that have no writing system.[6] Numbers Main article: Khmer numerals The numbers[13] are: 
