What is the structure of a Metaphor?

Implied metaphors, mixed metaphors, dead metaphors are considered as special cases of metaphor. More than special cases, these are more of different ways in which the concept of metaphor is applied and interpreted in English language.

A dead metaphor occurs when the original meaning of the comparison is lost either due to excessive repetition or a semantic shift (words losing or changing their initial meaning over time). For example: Roll up the window (Originally referring to the action of rolling up a window in a car, it now refers to closing a window in general).

This is an example of Standard metaphor which compares the two things directly. This metaphor 'Laughter is a medicine for the soul', compares laughter with medicine that cures and helps keeping good health.

Metaphor in English language is a figure of speech where we compare two unlike things without using 'like' or 'as'. They create a bright imaginary picture in the mind of the reader by using sensory details and descriptive language. For example: He has a heart of gold. (describing a person to be extremely kind, generous and empathetic).