(3) When the child has reached this stage when he begins to comprehend the practical importance of this activity of his vocal organs, he begins to imitate voluntarily, eagerly, the speech of grown people. This imitation is to some extent mechanical, without involving any comprehension of the meaning of the words. The child simply enjoys being able to produce the same words which grown people use. This imitation is in many cases at first very imperfect, because many elementary sounds necessary for these words have not been produced instinctively thus far and therefore cannot be produced voluntarily, the kinesthetic imagery being lacking. But soon even the more difficult sounds are produced accurately. The vocal organs acquire the habit of assuming certain normal positions, from which the special activity of speech in each case of pronunciation proceeds. In a few years the total number of words necessary for a command of the language is acquired. But voluntary imitation is not restricted to mere pronunciation. It is applied also to the modes of uniting words into compounds, phrases, sentences. The result of this application is the creation of new compounds out of the words which the child has at his command at the time, of new methods of applying inflection, to the amusement of those who surround him. The following are a few examples of such creations: _goed_ for _went_, _chair_ for _sitting_, _more pencil_ for _I want the other pencil_, _mussing down_ as the antonym of _mussing up_. Voluntary imitation, therefore, does not altogether mean assimilation to the language which the child hears spoken; to some extent it means departure from that language, resulting from the mental capacities with which he has been endowed by nature. In another way too the child’s language must differ from that of grown people. All acquisition of speech is based on perception and is subject to the laws of perception. We have previously seen that perception is largely dependent on the interest of the person who perceives, on his previous experiences.