Key Difference

• Biannual means something happens twice a year.
• Biennial means something happens once every two years.

1. Biannual

• Meaning: Occurring two times within a single year.
• Usage: Use “biannual” when you’re talking about events or actions that take place twice in the same year.
• Examples:
  • “We have a biannual meeting in March and September.”
  • “This magazine publishes biannual issues, one in summer and one in winter.”

🔄 Think of it as bi- (meaning two) + annual (year) = two times a year.

2. Biennial

• Meaning: Occurring once every two years.
• Usage: Use “biennial” for events or things that only happen once every other year.
• Examples:
  • “The art exhibit is biennial, taking place in odd-numbered years.”
  • “Our biennial family reunion is scheduled for next year.”

🔄 Biennial comes from biennium, meaning a two-year period.

Memory Tip

To remember the difference, think of “biannual” as happening two times in a year (like semiannual), while “biennial” is something that skips a year because it happens every two years.

Practice Time!

Fill in the blanks with “biannual” or “biennial”:

1. Our club has a __________ fundraiser in spring and fall.
2. The festival is __________ and won’t happen until 2025.
3. This company provides __________ updates to its investors in April and October.
4. There’s a __________ event to celebrate our town’s founding, held every two years.

Answers:

1. Biannual
2. Biennial
3. Biannual
4. Biennial