ばい

double

JLPT N4

Character Breakdown

Understanding 倍 (ばい)

The word 倍 (ばい) is used to express multiplication or how many times something is compared to a standard or original amount. It is commonly used in everyday conversation to talk about quantities, speed, size, or amounts that are multiples of something else.

Usage and Nuance

When you use 倍, you are indicating a scale or factor of increase or comparison. For example, 三倍 means "three times". It is often used with numbers and counters to describe how much larger or faster something is.

Common Collocations

  • 数字 + 倍: Expresses how many times (e.g., 二倍, 五倍)
  • 倍になる: To become double or multiply
  • 倍速で: At double speed

Register and Politeness

倍 is neutral and can be used in both casual and formal contexts. It is a straightforward quantitative term without emotional or honorific nuance.

Common Mistakes

Learners sometimes confuse 倍 with just "double" only, but it can express any multiple, not just two times. Also, 倍 is used with numbers, not with verbs directly. For example, you say "三倍の速さ" (three times the speed), not "三倍走る".

Use 倍 to clearly express multiples and comparisons in quantity or degree.

Example Sentences

このしょうひんはきょねんのうりあげのさんばいになりました。

This product's sales have become three times last year's.

かれはふつうのひとのにばいのはやさではしることができます。

He can run twice as fast as an average person.

きゅうりょうがばいになるのはうれしいけど、しごともばいたいへんになる。

It's nice that the salary doubles, but the work also becomes twice as hard.