Using words as alternative parts of speech:
An important characteristic of English to understand is that most words can be used as different parts of speech and have more than one meaning.
Learners need to develop knowledge of the alternative, grammatical uses of words. Knowing the various meanings of words is a pre-requisite to using them as superior alternatives to other words.
It is worth noting that some words are single lexical units or lexemes such as pneumonia and penicillin. These words have only one meaning each that never changes, regardless of the context in which they are used.
However, hundreds of thousands of words represent at least two or more lexemes. Many can be used as different parts of speech – with different meanings – depending on their function in a sentence.
Take for example the word “case”. As a verb, “case” can mean to “carefully survey” or “look over” some particular thing, as in this sentence: Professional thieves always case a place before they attempt to rob it.
“Case” can also be used as an adjective to mean “a record”, for example: My doctor keeps a case history on every patient.
And metallically, its meaning changes again, as in: That steel lid wascase-hardened.