Someone who says Bring me my faithful dog could easily have said it in a way that doesn’t share a single word with that utterance: Fetch that trusty hound of mine.

phonology (the systems of sounds in particular languages – some languages use barely a dozen consonants and vowels while others use hundreds);

But the key to what separates the cognitive powers of humans from those of all other creatures lies in the principles of syntax (sentence structure), semantics (literal meaning of sentences), and pragmatics (conveyance of utterance meaning in context).

Claims about the grammar of a language can be wrong in three different ways: (i) because the language has changed, (ii) because prejudice has clouded perceptions of what the facts are, or (iii) because of analytical blunders that obscure the description of the facts.

Sapir–Whorf Hypothesis. It’s supposed to be a hypothesis about how language shapes or determines thought, but it isn’t really a hypothesis at all. It’s a vaguely defined cluster of very different claims.

syntax (the ways words are combined into phrases and sentences – morphology and syntax are often lumped together as grammar);

I believe it’s the responsibility of linguists not to condemn what they see and hear but to frame their descriptions of English (or whatever language) in a way that captures the regularities that its fluent speakers typically employ when structuring their sentences.

human languages are structured systems for making articulated thoughts fully explicit both internally (mentally) and externally (in a form perceptible to other humans), and linguistics studies all components of such systems, together with the ways in which they are used.

linguist is interested in ascertaining what the actual grammatical constraints of the given language are.