This book was originally published in 1970. Aspect - the relationship between imperfective and perfective verbs - has always been one of the features of Russian grammar that English-speaking students find particularly difficult. It has in fact often appeared to be an insoluble mystery, largely because of the frequency of exceptions to the stated rules. Mr Forsyth suggests that this is the fault of the rules, and that the difficulties in the way of understanding the functioning of aspect stem chiefly from the faulty basis of the traditional definitions. The operation of imperfective and perfective are examined in all forms of the verb including the imperative, infinitive, participles and gerunds, and their usage is amply illustrated by examples from Russian. The aim is to present a total picture of aspect in the Russian language which will be of practical interest to advanced students of Russian, and also contributed to the theoretical study of aspect as a grammatical category.