Substitution (poetry)

In English poetry substitution, also known as inversion, is the use of an alien metric foot in a line of otherwise regular metrical pattern. For instance in an iambic line of "da DUM", a trochaic substitution would introduce a foot of "DUM da".

In a line of verse that normally employs iambic meter, trochaic substitution describes the replacement of an iamb by a trochee.

The following line from John Keats's To Autumn is straightforward iambic pentameter:

Using '°' for a weak syllable, '/' for a strong syllable, and '|' for divisions between feet it can be represented as:

The opening of a sonnet by John Donne demonstrates trochaic substitution of the first foot ("Batter"):

Donne uses an inversion (DUM da instead of da DUM) in the first foot of the first line to stress the key verb, "batter", and then sets up a clear iambic pattern with the rest of the line

Shakespeare's Hamlet includes a well-known example:

In the first line the word that is emphasized rather than is, which would be an unnatural accent. The first syllable of Whether is also stressed, making a trochaic beginning to the line.

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