This data archive includes experimental data from three behavioural experiments (lexical category judgement data, spelling, eyetracking-during-sentence-reading). The purpose of these experiments was to skilled readers’ sensitivity to spelling-to-meaning regularities in English suffixation. These data were presented at the Experimental Psychology Society meeting in 2017. Slides for this talk are also included in the archive. Please cite this talk as follows: Ulicheva, A., Harvey, H., Aronoff, M. & Rastle, K. (accepted). Statistical information encoded in English writing. *Cognition*. The .png figure (Diagnosticity_Specificity_all_words) is equivalent to Figure 2 in the accepted paper, but is based on all words (including those without any morphological structure, e.g. DISH). The file "Full analyses" includes all outputs from all mixed models of behavioural data (reported selectively in the accepted paper).