alternate

Everyday

1. To alternate means to change again and again between two things, one after the other: red, blue, red, blue. tree →
2. As an adjective, alternate means every second one: «on alternate days» = one day yes, one day no. tree →
3. In US English alternate also means another one you can use instead (an alternate route); a person who can take someone's place is an alternate. tree →

In the lessons

In maths, alternating patterns repeat (ABAB), and «alternate numbers» are every other number (1, 3, 5…). In geometry, «alternate angles» are equal angles on opposite sides of a line crossing two parallel lines. In everyday life you take turns («alternate» who goes first) and some families alternate weekends. Phrases: «alternate between», «on alternate days», «alternate angles», «alternating current» (AC, in science).

Examples

• Alternate red and yellow beads on the string. tree →
• We have PE on alternate days. tree →
• The weather alternated between sun and rain. tree →
• Take alternate steps on the stones to cross. tree →
• Write the alternate numbers from 2: 2, 4, 6, 8. tree →
• Mark the alternate angles on the parallel lines. tree →
• The two brothers alternate washing and drying the dishes. tree →
• If the road is closed, take an alternate route. tree →
• Zeus gave the desired permission, and the faithful brothers were both allowed to live, but only on alternate days. tree →

Note

Pronunciation differs: adjective/noun «al-TER-nut» (UK) or «AWL-ter-nut» (US); verb «AWL-ter-nate». Trap: UK English «alternate» = every second one; «alternative» = another choice. Americans often use «alternate» for both. In maths, «on alternate days for 10 days» = 5 days.