Difference Between Bi and Semi

Bi vs Semi

The prefixes semi and bi are used very commonly in daily life conversations and are rather simple to understand. However, for non-native speakers, these prefixes can create big confusion, and they can distort the meaning of a text altogether if they get it wrong. This article attempts to clarify the differences between bi and semi once and for all.

The confusion between the two prefixes bi and semi arises mainly because both are related with the concept of two. But, whereas bi is used to indicate an event that takes place every two or every other week, month or year, semi is used to indicate events that take place twice every week or month or year. Thus, we have biennial magazine that is published every two years, and a salary distributed semi monthly, which means that it is given every 15 days.

Both semi and bi have Latin roots. Semi means half, and bi means two. Thus, we have semi finals meaning two halves of the final, we also have bi weekly magazine implying one that is published every two weeks. Thus, no confusion when the words semi monthly and bi-monthly are uttered, as bi-monthly would refer to an event taking place every two months, whereas semi-monthly would refer to the event taking place twice in a month.

The confusion to many arises with biannual and biennial. Biennial certainly means every two years, biannual can mean both twice a year OR every two years, which is very confusing. In situations like these, it is better to make things clear what you have in mind such as every other month or twice a month, whichever is on your mind. Thus, it makes sense to use every other or twice, in place of semi and bi.

What is the difference between Bi and Semi?

• Semi comes from a Latin word meaning half.

• Bi comes from a Latin word meaning two.

• Thus, a semi final (There are two of them) is before the final event.

• Biennial publication means one that takes place every two years.

• Semi-monthly would thus indicate an event taking place twice a month or every 15 days.

• Bi is every two; so we have biweekly, bimonthly, and biyearly implying something taking place every two weeks, every two months, and every two years respectively.