5.117 regular intervals

If you want to say that something happens at regular intervals, you can use 'every' followed by either a general or a specific unit of time. 'Each' is sometimes used instead of 'every'.

'Every' can also be used with a number and the plural of the unit of time.

The regular or average rate or quantity of something can also be expressed using 'every' and 'each'.

5.118

If something happens during one period of time but not during the next period, then happens again during the next, and so on, you can use 'every other' followed by a unit of time or a specific time word. 'Every second' is sometimes used instead of 'every other'.

Prepositional phrases with 'alternate' and a plural time word can also be used.