verb / adjective
alternate
To take turns in a recurring sequence.
The wooden tiles alternate red and blue along the row.

Etymology
Latin alternare meant to do things by turns. This use preserves the recurring exchange, in which one participant or state gives way to another and then returns.
In context
philosophers use possible worlds almost like alternate realities so look at how things could have been
More examples
- We take turns cooking on alternate evenings.
- She alternated short runs with periods of walking.
- Sunshine and showers are alternating throughout the afternoon.
Forms
alternate · alternates · alternated · alternating
alternation noun — A recurring switch between actions or conditions.
Similar words
- rotate
- Often cycles through several positions rather than switching between two.
- interchange
- Can describe swapping items without a recurring sequence.