Although some research found some primates can develop language. But we are the only species can speak language with sound, however, other animals can develop language given different media. 170 words, the same level as two-year old child: other primates can use tools. Development in language and speech: they are different things. Language can use movements, such as movements: phonological (sound): most basic and most simple component. Coos and babble are pleasurable for babies to make sounds. The most motivating thing in human is attention, those sounds can draw attention. (oxytocin releases make you like hug!) Sound system of language; how sounds are used, combined--phoneme: smallest unit of sound. English language is tend to be vowels based. English has 5 vowels: a e i o u, and sometimes y: semantic (meaning): there is meaning to the sound. Morphemes: units of meaning in word formation. Suffix and prefix: they have meaning but they are not words.