The purpose of this paper, as the subtitle suggests, is two-fold. First, it will assert the emergence of (yi)zhengge '(一)整個' as an intensive/emphatic marker among young speakers in Taiwan Mandarin Chinese, e.g. yizhengge hen youqu 'all very interesting, lit. one.whole.intensifier. classifer/GE.interesting'; secondly, it will proceed to trace its gramma-ticalization development from a corpus-based perspective.We will argue that (yi)zhengge starts with a pre-nominal modifier, e.g. zhengge zhetou 'the entire front of the vehicle', and then assumes its anaphoric/post-nominal use pragmatically, e.g. zhetou zhengge zhuang de niuqu bianxing 'the entire front of the vehicle was crashed and distorted' (FTV News, 01/06/2001), in which zhengge is intended for the noun zhetou 'front of the vehicle' rather than the verb zhuang 'to crash'. Post-nominal zhengge undergoes re-analysis into an adverb, which later-on gives rise to its use as an intensifier, e.g. zhengge gaibian 'completely change' (Sinica Corpus) and zhengge xia 'totally senseless' (Web link 1). We will conclude the paper by comparing (yi)zhengge with ALL in English (Rickford et al., 2007) and zhegge yi(ge) in Putonghua (CCL Corpus). We will also suggest that besides being an indefinite article (Liu, to appear), yige may be used as an intensifier in such a construction as …dao (yige)…'to (yige) …', where yige, if present, is used interchangeably with zhengge and yizhengge, e.g. Lin Chiling mei dao (yige/zhengge/yizhengge) buxing. 'Chiling Lin is extremely pretty. lit. Chiling Lin is pretty to death.' While one may argue that yige in dao yige dibu/jingjie is an indefinite article, the parallel dao yige buxing suggests that yige contributes to the gradable/extreme reading of the construction (Gorishneva, 2009).Because of its distribution, we hypothesize that (yi)zhengge is primarily a (pre-)nominal modifier. Evidence from Sinica Corpus indicates that over 95% (1397/1454) of zhengge is followed by nominals. Among the 45 occurrences of zhengge + verbal construction, 42 of them are anaphoric and refer back to a preceding nominal. No use of intensive (yi)zhengge is observed from Sinica Corpus, and a Conversational Corpus built at National Taiwan University. We turn to Google Twitter Search, and 'in-site' web search of Moble01 and FTV News for data. Evidence suggests that (yi)zhengge has emerged as an intensifier by 2006. Due to the failure of linguistic corpora to incorporate emerging linguistic change(s) such as the (yi)zhengge in question, mining linguistic data for analysis from the Internet, specifically social media, and incorporate them to build a truly balanced linguistic corpus is thus worth linguists' efforts.