This study sought to provide evidence for the existence of specific grammatical features which one could definitely say are characteristic of Kenyan English. Using a questionnaire, it gauged the extent of acceptability of twenty-six features by between 75 and 188 respondents. The twenty-six features appeared in sentences that would be considered as deviant in standard international English, and informants were instructed to correct errors in them. The sample of respondents was drawn, over a two-year period, from eight classes of students specializing in either linguistics or communication at the University of Nairobi. The target features covered “grammar” in its widest sense: from punctuation marks and spelling to morphological, syntactic and lexical aspects. The results showed that fourteen (i.e. 54%) of the twenty-six structures scored acceptability ratings of at least 60%. These could be argued to be indeed characteristic of at least written Kenyan English. But, with acceptability ratings for some other structures being as low as only two and eighteen percent, the results equally suggest that some apparently very common features of Kenyan English would only be accepted in spoken, rather than written language.