The paper analyzes functioning in the child's mind of an inner motivational mechanism aimed at outward vocal manifestation. The motivation takes the form of the so-called "intentions", i.e. the intention to give an outward expression to some psychological experiences. The paper contains empirical data on development of a child's intentions from birth to 2 years of age, arguing natural determination of inner links between intentions and the child's speech development. The authors discuss emergence of verbal imitations and the mechanism of development of the first word imitations in an infant. The authors also describe a technique for effective overcoming of slow speech development in a group of children with the help of specially constructed therapeutic classes.