Language tip of the week: decrease

In this weekly post, we bring more useful content from the Macmillan Dictionary to English language learners. These tips are usually based on areas of English which learners find difficult, e.g. spelling, grammar, collocation, synonyms, etc.

This week’s language tip helps with using the patterns that follow the noun decrease. Don’t use decrease of when you want to talk about what is decreasing. Use decrease in:

✗ The experiment has not led to the expected ~~decrease of~~ crime.
✓ The experiment has not led to the expected decrease in crime.
✗ There has been a ~~decrease of~~ the birth rate in the industrialized world.
✓ There has been a decrease in the birth rate in the industrialized world.

Use decrease of with a number or percentage, when you want to talk about the amount by which something decreases:

These emissions show a decrease of 21 percent over the past five years.