In Old English, the notions of number and case were always expressed by one morpheme. Thus, in the Old English form stana the ending -a expressed simultaneously the plural number and the genitive case. That was typical of an inflected language. A change came already in Middle English, and in Modern English the two notions have been entirely separated. This is especially clear in the nouns which do not form their plural in -s: in the forms men's, children's number is expressed by the root vowel and the inflection -ren, while the -'s expresses case alone. But this applies to nouns forming their plural in -s as well. E. g. in father's the -'s expresses possessivity, whereas the notion of singular has no material expression. In the plural fathers' the -s expresses the plural number, whereas the notion of possessivity has no material expression in pronunciation (in the written language it is expressed by the apostrophe standing after the -s). In spoken English the two forms may of course be confused. Thus, in the phrase [Ээ 'boiz 'buks] it is impossible to tell whether one or more boys are meant (in written English these variants would be distinguished by the place of the apostrophe: the boy's books as against the boys' books), unless the context gives a clue. Thus, in [mai 'mAЭэz э'pinjэn] it is obvious that my mother's (singular) is meant, whereas in [auэ 'mAЭэz э'pinjэnz] the meaning is doubtful (our mother's or our mothers'?). It is natural, therefore, that ambiguity is better avoided by using the of-phrase instead of the possessive, e. g. the opinions of our mothers, etc. Another view of the case system in English nouns must also be mentioned here, namely the view that we should distinguish between a nominative and an objective case, though there is no difference between the two in any English noun.  Such a differen tiation could only be based on the fact that personal pronouns (I, he, she, we, they) and the pronoun who have different forms for these cases (I — me, etc.). If, therefore, we start on the assumption that the system of cases is bound to be the same in these pronouns and in all nouns, we shall be led to acknowledge the two cases in nouns. However, there would seem to be no necessity to endorse this view. It is probably more advisable to consider the case system of nouns without taking into account that of the personal pronouns.