This study sought to investigate whether there was correlation between reading impairment (dyslexia) and writing impairment (dysgraphia), and whether function words would pose a greater challenge than content words in both reading and writing in the English of a group of twenty-five upper-primary pupils (of the Sabatia Sub-county of Vihiga County, Kenya) who experienced serious reading and writing difficulties. It found that there was a high positive correlation between the subjects’ reading and writing (r = 0.79 at p<0.01, with df =23). However, contrary to what had been hypothesized (based on the available literature on language disorders), it found that the subjects’ performance on both reading and writing function words was significantly better than that on reading and writing content words (with calculated chi-square values of 45.62 for reading and of 30.46 for writing). Overall, the study’s results show that when the target words were presented in a list (i.e. in isolation), there was no statistical difference in the subjects’ performance on reading and that on writing, but when they were presented in sentences (i.e. in context), the subjects did significantly better on reading than on writing, both for content and function words. However, in absolute terms they did poorly on both reading and writing, well below a 50% correct-reading and correct-spelling rate.