The Dash ( – )

The dash is used, rather indiscriminately, for various purposes. It may replace a comma where a stronger break is required. It may be used in place of parentheses, the colon and the semicolon. Often it is used, in a rather informal or conversational style, to drop an interrupting phrase into a sentence.

A dash is not the same as a hyphen. It is used in a different way and it is longer than a hyphen. It may not be present on all keyboards, but you can create a dash by pressing the hyphen along with the ALT or OPTION key. This will give you an en dash (slightly longer than a hyphen). You can create an em dash (slightly longer still) by pressing the hyphen along with the SHIFT + ALT or OPTION key.

Interrupting Phrases

An interrupting phrase may be an appositive, an example, or an explanatory aside.

• The planet Saturn is very oblate – non-spherical – because it rotates very fast.
• A spore is made of just one part – a single cell – while a seed contains many cells, each with different jobs to do.
  This appositive noun phrase would be just as happy resting between two commas.
• Small-world play – such as with dolls houses or toy farm sets – can be used to help children learn to see things from other viewpoints and understand differences in spatial scale. 
• Imagine you place a heavy bowling ball in the centre of a trampoline – its mass bends the fabric, and it creates a dip .  

Coordinated Clauses

• It’s easier for gametophytes to join together when its wet – and that’s why plants that use spores usually need to grow in wet places .
• Modern life is full of distractions – and some of them can have a negative effect on our ability to concentrate when studying .
• Ultra-processed foods are designed to be hyper-palatable – and together with persuasive marketing, this can make resisting them an enormous challenge for some people .

Final Phrases

Dashes are used to give emphasis to a final word or phrase of a sentence.

• Imagine how a drop of food coloring spreads in a glass of water – dash introducing final phrasethat’s diffusionfinal phrase.
• Human impact spans the entire globe – from the land to sea, and the south pole to the north pole .
• Ice is more reflective than water, and snow is extremely reflective – more so than ice or water more so than ice or waterfinal phrase.

Test your understanding of dash punctuation with the Dash Punctuation Quiz.