While ordinary speakers - and some linguists - assume we have a mental dictionary stocked with words ready for use, Walter Hirtle shows that this view leads to contradictions. Focusing on the English noun with its modifiers and determiners, he proposes a radically different approach, arguing that a word's meaning is formed from formative elements each time we use it.

Distinguishing the components that make up the meaning of a noun enables us to understand what permits us to say "Ground temperature plus one degrees," or to invent "small is beautiful." A careful look at the meaning and role of -'s and of words like a/the, any/some, this/that, often found in noun phrases, reveals how they refer to the speaker's message. Examining pronouns pin-points the fundamental role of the representation of a grammatical person in all noun phrases.

Based on Guillaume's theory of the word, Lessons on the Noun Phrase in English proposes a word-based analysis of the mental operations involved in producing a noun phrase, starting with representing the speaker's message, then relating the words, and finishing with reference back to the message. In outlining the theory, Hirtle reveals the marvellous feat we accomplish each time we speak.