Answer:
a. cooing, babbling, understanding single words, verbalizing single words
Step-by-step explanation:
All human beings are equipped with the capacity to develop a language, and it is social interaction that determines which language they eventually learn. This process of language acquisition starts at the early childhood or babyhood and has different stages. The common sequence for language development starts with cooing, that is, the production of the first-vowel-sounds during the two or three months of life. Babbling follows cooing and starts around 4 months of age. In this stage the consonant sounds will begin to mix with vowels and the child starts practicing different sounds, rhythms, and intonations of speech. After the seven months, the baby starts understanding single words, as he or she can recognize words for common objects and names of family members and also respond to simple requests . The baby learns language by listening and certainly doesn't understand everything, but there is no doubt that he/she can pick up glimmers of meaning. Finally, the verbalizing of single words takes place. If you speak to your baby a lot, he/she will understand many words before uttering anything recognizable.This gap between child's understanding and his ability to verbalize will continue throughout the preschool years. The child will understand much more than he can put into words himself and this comparatively deeper understanding paves the way for verbalization.