The level of mastery of selected language forms among English as a second language students in Botswana was investigated. Eighty-four pupils in the third to the sixth year of formal education provided oral English samples in unstructured formats involving language experience stories. The oral language of the pupils was analyzed to establish the sequence in which certain English features were learned. Most stories produced by the younger pupils consisted of naming objects in the picture, while the older students added content from other classes. The contracted copula and possessives did not regularly occur in the pupils' stories. The younger students used articles and pronouns with great frequency. However, the highest frequency of errors was with articles and pronouns. The older students used more prepositions while committing errors of omission of articles, third person errors, and "be" verb and regular past errors. It is concluded that the marked differences between the number of features used by younger and older students implies that when pupils are taught content subjects in Enlgish, their production of English features is more varied. (RW)