There are three major groups of words: lexical words, function words and inserts.
You can watch the video version here:
Lexical Words
LEXICAL WORDS are words which carry a concrete meaning. Here belong nouns, verbs, adjectives and adverbs, so all the open classes of words.
Lexical words are crucial to understand the meaning of a text or piece of information. Even if you leave out all the other words and keep just the lexical words, the meaning will be understandable. This is often used in headlines or telegrams. Here’s an example of a headline:
Missing Link Found in Australia
As you can see, most of the function words have been removed and only the lexical ones have been maintained. Still, the meaning is clear.
Function Words
FUNCTION WORDS do not carry a meaning themselves. They bind lexical words and create relationships between them. They also help you interpret lexical words in a text.
These words belong to the closed classes, like conjunctions, prepositions.
Here are the main differences between the two types of words discussed above:
| feature | lexical words | function words |
| number | There’s an unlimited number of lexical words, because they belong to the open classes. | There’s a limited and relatively small number of function words, because they belong to the closed classes. |
| length | Lexical words may be of any length. | Most function words are short. |
| frequency | Lexical words occur with low frequencies. Some of them only occur in specialized texts. | They occur frequently in any text. Some occur more frequently than others, though. |
| lexical meaning | Lexical words carry a meaning. | Function words don’t have a lexical meaning. |
| morphology | Lexical words are variable. They can be inflected. | Function words are invariable. |
| stress | Lexical words usually carry the primary or secondary stress. | Function words are usually unstressed and often reduced. |
| role in phrase | Lexical words can be the heads of phrases. | Function words are never the heads of phrases. |
Inserts
Finally, there are INSERTS. These are words that are inserted relatively freely in a text to add some emotional or interactional value. They include words like: YES, YEAH, NO, NOPE, HM, UGH, UHHUH and such like.
In spoken language they are often marked by intonation or pauses, in written language by punctuation. They are rather typical of spoken language, but they can appear in written language as well, especially if it imitates spoken language, like in dialogues.
Inserts play an important role in communication. Many inserts are spelled inconsistently.