THE PARTS OF SPEECH IN THE CHILD’S LINGUISTIC 
DEVELOPMENT. 1 
M. V. O’SHEA, 
Professor of Education, University of Wisconsin. 
1. SENTENCE WORDS. 
A number of students of infant linguistics, as Holden, 2 
Humphreys, 3 Tracy, 4 et al, have endeavored to determine the 
relative frequency of the several parts of speech in the child’s 
language during successive periods in his early linguistic de¬ 
velopment. They have made lists of all the words spoken by 
a number of children between the ages of fifteen months and 
three years approximately, classifying them according to the 
standard grammatical categories. Following this method of 
1 It should be explained that this essay comprises a short chapter ab¬ 
stracted from a larger study on the Psychology of Linguistic Develop¬ 
ment, which it is hoped may some time later be brought to the light. 
It will be presented in two parts: 1. The Non-reflective Processes 
in Linguistic Development; II. The Reflective Process in Lin¬ 
guistic Development. The present essay is Chapter III of Part I of this 
study; and the chapters which precede and follow it should, if space 
permitted, be given in order that it might have the proper setting. As 
it is, however, I must be content with saying simply that the first two 
chapters treat of Pre-Linguistic Activity, and the Earliest Reactions 
upon Conventional Language. The chapters which follow the present 
one in Part I treat of the Development of 'Inflection in Early Language ; 
the Order of Words in Sentential Construction; and the Development 
of Verbal Signification. Part II treats of the psychology of the various 
phases of linguistic instruction in the mother tongue and in foreign 
language; and it discusses current theory and practice at home and 
abroad in respect of language training. 
2 On the Vocabularies of Children Under Two Years of Age; Trans. 
Am. Phil. Assn. 1877, pp. 58 et seq. 
3 A contribution to Infantile Linguistics; Trans. Am. Phil. Assn. 1880, 
pp. 5 et seq. 
4 Psychology of Childhood, Chap. V. 
