A lexicon is the inventory of lexical items of a language.

A lexicon is a mental dictionary or a list of lexical items and their properties. Contains all the irregular and memorized parts of language.

A dictionary represents an attempt at listing in alphabetical order the lexicon of a given language.


1   Form

A lexicon consists of lexical entries.

A lexical item is a single word, a part of a word, or a chain of words that forms the basic elements of a language's lexicon. For example, "cat", "traffic light", "take care of", "by the way", and "it's raining cats and dogs". Lexical items convey a single meaning, but are not limited to single words.

A lexical entry contains at least the following:

When you learn a new word, you memorize all this information.

The entire store of lexical items in a language is called its lexis.

A lexis is the total word-stock or lexicon have items of lexical, rather than grammatical, meaning.

2   Classification

A polarity item is a lexical item that can appear only in environments associated with a particular grammatical polarity - affirmative or negative. A polarity item that appears in affirmative (positive) context is called a positive polarity item (PPI), and one that appears in negative contexts is negative polarity item (NPI).

For example, consider "I don't know a single thing" and *"I know a single thing".