reason

reason

CEFR: A1-A2 /rea-son/ [r.iy1.z.ah0.n]

One/The reason for _____ is ____.

Let’s look at the following examples:

Example Sentences:
One reason why the population is growing so fast is that death rates have fallen dramatically
One reason why the population is growing so fast is the drastic decline in the death rates.
The reason for overpopulation is that resources are limited.

The adjectives "primary" and "main" are often used with the word "reason". Using this, you can change the last sentence like this:

Example Sentences:
The primary/main reason for overpopulation is that resources are limited.