According to the nativist theory, we are born with a language acquisition device that allows us to learn language as children. We are all born with this mechanism, regardless of what language we speak or what methods of instruction are used to teach us how to speak. 

The language acquisition device is a hypothetical construct crafted by Chomsky that indicates that humans are unique in their ability to understand language from a young age. Young infants can acquire and produce language and begin to understand both its syntax and grammar. In this way, only humans can understand language, as humans are the only species that have such a disposition from birth (as opposed to developing such a disposition from exposure to language).

Onsets are consonants that begin a syllable. The onset of the syllable [bat] is [b]. Codas are consonants that end a syllable. The coda of the syllable [bat] is [t].

Generally speaking, languages tend to prefer to have syllable structures that have an onset but no coda. For instance, there are theoretically two different ways to syllabify the word "kitten". It could be [kit]-[ten] where the [t] is a coda of [kit]. Or, the way we actually say it, [ki][tten] where the first syllable has no coda at all.

There are of course exceptions that can't be discussed at length here, but this is a general phonological rule that guides sound structure. 

Semantic ambiguity is the opposite of structural ambiguity. Semantic ambiguity is when the structure of a sentence is restricted to one particular structure but a word in the sentence makes it ambiguous. For instance, the word "bat" in the sentence "I touched the bat" can mean the animal or a baseball bat.

Ellipsis is when a word is omitted in a sentence since it is likely that the word will be filled in by the audience. Ellipsis makes our sentences more efficient to produce and less repetitive. For instance, instead of saying "John ran to the store and John talked to the clerk" we can "ellide" (use ellipsis) "John" and say "John ran to the store and talked to the clerk". In fact, we use ellipsis so much that if we were to use "John" twice in that sentence it may sound like we were talking about two different Johns!

Language can reveal many things about a person's beliefs, state of being, and even underlying mental conditions. This is not restricted to what the person is trying to convey in meaning but the actual structure of their sentences or word choices. For instance, a linguist could look at two passages written by different people about the same event and conclude many things about each person's personality. One person may have used "I" many times in telling the story, which reflects valuing their subjective experience over objective fact. The other may have used a combination of writing conventions that indicate value in both both subjectivity and objectivity related to the retelling of the event. Psychologists can even analyze speech to see if a person has a serious mental condition such as schizophrenia or psychopathy.

Minimal pairs are used in phonology to find sounds that lie in contrastive distribution which make them phonemes of a language. Minimal pairs are words that are only separated by one sound. For instance, "fate" and "bait" are separated by the first sounds "f" and "b" and otherwise sound the same. This means that "f" and "b" are phonemes of English: they are sounds that distinguish between the meaning of words.

Think hard about the following sentence:"Flying planes can be dangerous."

Did you think of two different meanings or just one? There are actually two and this is due to structural ambiguity. One meaning is that a person flying a plane will be in danger. The other is that planes that are flying are dangerous. In the first meaning, we think of the action of "flying;" thus, flying is a verb performed by some unknown agent. In the second meaning, we think of "flying" as an adjective for "planes" thus planes that are flying in the air are dangerous.

This sentence is structurally ambiguous with two fathomable structural interpretations. One is that John was using a telescope and saw a man. This interpretation makes the noun "John" and the prepositional phrase "with the telescope" related at a higher level. The other is that John saw a man and this man had a telescope. This relates the noun phrase "a man" closely related with "with the telescope". There are only two different ways of syntactically combining this particular sentence according to the rules of English and thus only two structural interpretations. 

A representativeness heuristic is the idea that a small sample of known individuals can provide defining characteristics for a larger population. All of the birds that Kevin correctly identified are small and can fly; because the ostrich is large and cannot fly, it does not display the characteristics that Kevin believed all birds must have.