English place-names ending in -wich and -wick (henceforth EPNWh and EPNWk, respectively) sometimes exhibit /w/-deletion, which is idiosyncratic in English phonology. For example, the suffix-initial /w/ is deleted after certain root-final consonants like /r/, /l/, /n/, and /m/: e.g. Norwich [nɔrɪʧ], Greenwich [grɪnɪʧ], Woolwich [wʊlɪʧ], Bromwich [brɔmɪʧ], Warwick [wɔrɪk], Alnwick [ænɪk]. After other segments, on the other hand, the suffix-initial /w/ is pronounced, as in Ipswich [ɪpswɪʧ], Northwich [nɔɵwɪʧ], Gatwick [gætwɪk]. Pickwick [pɪkwɪk], etc. This study conducted an online survey experiment using written forms to identify native speaker’s knowledge of morpheme-specific phonology involved in EPNWh and EPNWk. Total 42 actual and nonce words are tested by 43 respondents. The result is that morpheme-specific phonology in EPNWh and EPNWk was not equally productive to native speakers of British English. The suffix -wich was more likely to trigger /w/-deletion than -wick. The -wich was much more likely to delete /w/ than hypothetical -wid. However, the difference between -wick and -wid was not statistically significant. In addition, derivational rule-ordering in EPNWh and EPNWh was not sensitive to suffixes. Nevertheless, some native speakers equally reflected derivation in pronouncing the place-names.