The starting point for the paper is the assumption that Old English and contemporary German share many grammatical similarities. English and German are historically closely related, which is reflected in the fact that both languages are classified into the West Germanic group of the Germanic branch of the Indo-European language family. The main aim of the paper is to find and describe the similarities and differences between these two languages, that is between the two phases in their respective historical development. A combination of the diachronic, comparative and contrastive methods is used to do so. The paper compares and contrasts pronouns, articles, nouns and adjectives, that is their properties that are typical of both Old English and contemporary German. The introductory chapter describes some of the phonological changes that are necessary for understanding the similarities and differences in pronunciation. It has been included in the paper based on the conclusion that there is a significant level of correlation between certain phonemes and the choice of inflectional suffixes in both languages. Due to the vast temporal gap between the two phases in the respective historical development of English and German, the paper ignores the influence of the Norman Conquest of 1066 on the historical development of the English language, except for the fact that it does attempt to describe which of the typically Germanic, or West Germanic, grammatical features it lacks in its contemporary form.