Posted: September 19, 2023

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Definition: a punctuation mark (/) once used to mark periods and commas, the slash is now used to represent division and fractions, exclusive ‘or’ and inclusive ‘or,’ and as a date separator.

Note: Do not rely on grammar or spelling checkers to identify missing or misused punctuation. Although a checker may flag possibly missing or incorrect marks, it cannot do much else. While I still recommend using these AI checkers while you’re writing, I insist that you also trust a qualified human being to copyedit any work that you are working toward publishing.

A slash can also be called a solidus, diagonal, or shilling, and is mostly used in mathematical copy. It can also be sed to indicate options, to mark the end of a line of poetry in text, and to stand in for the word per. It can be further distinguished as a forward slash, as its reverse is called a backslash. Finally, there is a vertical slash, which is primarily used in coding and mathematics.

In Options:

Use a slash when multiple options are interchangeable.

• e.g. “I’m going to the beach with Makayla and/or Chelsey; want to come?”
• e.g. When an author publishes a book, he/she receives a portion of the royalties on every copy sold.
• e.g. Use a black pen/pencil to fill in the answers on the test.

To Set off Poetry:

When including lines of poetry within prose, use a slash to indicate the end of the line.

• e.g. Dickenson began one of his most famous poems with “Because I could not stop for Death / He kindly stopped for me.”

In Place of Per:

Use a slash in place of per when writing measurements (of speed, distance, etc.).

• e.g. He reached speeds of 150 km/hr. [150 kilometres per hour]

In Fractions:

Use a slash between two numbers to indicate a fraction.

• e.g. ¾ [three quarters]

In Dates:

Use a slash between the numbers of a date.

• e.g. DD/MM/YYYY or 22/09/1995 [22 September 1995]

Note: Different countries order their dates differently. American English writes month – day – year, while British English writes day – month – year.

For further information, see my other Punctuation articles:

Sources:

Aaron, J.E. & Morrison, A. The Little, Brown Compact Handbook, 5th Canadian ed. Pearson, 2013, chap 5
Judd, K. Copyediting, A Practical Guide, 3rd ed. California, CA: Crisp Learning, 2001, chap 4