Erhua (simplified Chinese: 儿化; traditional Chinese: 兒化; pinyin: érhuà), also called "erization" or "rhotacization of syllable finals", is a phonological process that adds r-coloring or the er (儿; 兒 [ɚ]) sound to syllables in spoken Mandarin Chinese. Erhuayin (儿化音; 兒化音) is the pronunciation of "er" after rhotacization of syllable finals.
It is common in most varieties of Mandarin as a diminutive suffix for nouns, though some dialects also use it for other grammatical purposes. The Standard Chinese spoken in government-produced educational and examination recordings features erhua to some extent, as in 哪儿 nǎr 'where', 一点儿 yìdiǎnr 'a little', and 好玩儿 hǎowánr 'fun'. Colloquial speech in many dialects especially in northern China has more extensive erhua than the standardized language. Southwestern Mandarin dialects such as those of Chongqing and Chengdu also have erhua. By contrast, many southern Chinese such as in Fujian and Guangdong who speak their own languages may have difficulty pronouncing the sound or may simply prefer not to pronounce it, and usually avoid words with erhua when speaking Standard Chinese; for example, the three examples listed above may be replaced with the synonyms 哪里 nǎlǐ, 一点 yìdiǎn, 好玩 hǎowán. Furthermore, erhua is extremely rare or absent in Mandarin speakers from Singapore and Taiwan.