Language: 

Babbling Stage

• at about 4-7 months
• stage of speech development where the infant spontaneously utters various sounds at first unrelated to household language 

This is a video of twin babies having a conversation with each other. They are still in the babbling stage.

Benjamin Whorf

• his theory is that language determines the way we think

Grammar 

• determines how sounds and words can be combined
• used to communicate meaning within a language
• has two components which are syntax and semantics.

Morpheme 

• smallest meaningful units of speech
• simple words, suffixes, or prefixes
• Ex: calm, hot

Phonemes 

• basic sounds units 
• indicates the change in meaning

One-word Stage

• the stage in speech development where a child speaks mostly in single words
• from about 1 to 2 years old

Two-word Stage

• beginning at about 2 years old
• stage in speech development where a child speaks two worded statements

Semantics

• the study of meaning in language

Syntax

• studies of the rules for forming admissible sentences

Telegraphic Stage

• early speech stage where the child talks like a telegram
• Ex: "Go car"

Noam Chomsky 

• Stated there is an infinite number of sentences in a language
• humans have an inborn native ability to develop language