Sometimes when people speak Chinese they pronounce "zh" more like "z", "ch" like "c", "sh" more like "s", etc. In other respects (sentence structure, words), it seems to be proper mandarin. An example from Silicon valley:
https://www.youtube.com/watch?v=v201VzV5GIA&feature=youtu.be&t=1m04s
It seems like the person in a shirt is saying "zeige feicang zongyao" where it should be "zheige feichang zhongyao" (这个非常重要)
Is it an accent or dialect? What's it called?
翹舌音
翘舌音[翹舌音]
qiàoshéyīn
retroflex sound (e.g. in Mandarin zh, ch, sh, r)
It could be accent, it could be dialect it could be 大舌头 (a big tongue).
翘舌音 is almost nonexistent in Taiwan, although it should be, so I'd say that's down to accent.
Many topolects, like Sichuanese, don't carry retroflex sounds, and that's dialectical.
Some people do have speech impediments or just a big tongue, as some like to put it.
You can call it lack of retroflex or 没有翘舌音.
The guy in the scene from Silicon Valley seems to be channeling a Taiwanese accent.
