Although the Beijing dialect and Standard Mandarin are extremely similar, there are some differences that make it easy for Chinese people to tell between a native of Beijing speaking homegrown Beijing dialect, and a non-native of Beijing speaking Standard Mandarin.
For example, the local speech of Chengde, a city north of Beijing, is considered sufficiently close to Beijing dialect to be put into this category. Standard Mandarin is also put into this category, since it is based on the local dialect of Beijing. Other examples include the local speech of Hailar, Inner Mongolia; Karamay, Xinjiang; and (increasingly) Shenzhen, Guangdong. Many of these cities are populated by recent Han Chinese immigrants from diverse linguistic backgrounds or their descendants. As a result, the residents of these cities have adopted standard Mandarin (or something very close to it) as the de facto common language.
However, there are some striking differences. Most prominently is the proliferation of rhotic vowels. All rhotic vowels are the result of -儿 /-ɹ/, a noun suffix, except for a few words pronounced as /ɑɹ/ that do not have this suffix. In Standard Mandarin, these also occur, but nowhere near the ubiquity and frequency in which they appear in Beijing dialect. This phenomenon is known as (儿化).
Moreover, Beijing dialect has a few phonetic reductions that are usually considered too "slangy" for use in Standard Mandarin. For example, in fast speech, initial consonants go through lenition if they are in an unstressed syllable: pinyin become r /ɻ/, so 不知道 "don't know" can sound like (stress is on the first and third syllables); j q x become y /j/, so 赶紧去 "go quickly" can sound like ; pinyin b d g /p t k/ go through voicing to become [b d g]; similar changes also occur on other consonants. Also, final /-n/ and (less frequently) /-ŋ/ (-ng) can fail to close entirely, so that a nasal vowel is pronounced instead of a nasal consonant; for example, 您 ends up sounding like "" (nasalized), instead of "" in Standard Mandarin:
|Pinyin||Standard Mandarin|| Typical pronunciation |
Note that some of the slang are considered to be (土话), or "base language", that are carryovers from an older generation and are no longer used amongst more educated individuals, for example:
Others, still, can be construed as neologistic expressions that are used amongst "trendier" crowds:
As with phonology and vocabulary, the grammar of the colloquial Beijing dialect utilizes more colloquial expressions than does Standard Mandarin. In general, Standard Mandarin is influenced by Classical Chinese, which makes it more condensed and concise; Beijing dialect is not influenced in this way, and can therefore seem more longwinded — though this is made up by the fact that Beijing dialect is spoken faster and has phonetic reductions (see Phonology section above).
The Beijing dialect sentence would sound too long-winded if used in a context that requires Standard Mandarin (e.g. in writing, or formal speech), though it sounds fine if used among Beijing locals (with Beijing phonetic reductions in place). The Standard Mandarin pronunciation sounds fine if it is used in a context that requires it (e.g. among friends from different Chinese regions), but it is too stilted and short to be able to accommodate all the phonetic reductions of Beijing pronunciation and may be rendered incomprehensible as a result.