The verb "decrease" can be used with or without the object (because the verb can be both transitive and intransitive).The verb "reduce" requires an object (because it is a transitive verb)
While the verb "decrease" can always replace "reduce", not always can "reduce" replace "decrease".
I've decreased/reduced the amount of fat I eat.
PayPal reduced/decreased credit limits.
Credit limits on PayPal have DECREASED. - OK, because "decrease" can be used without an object.
Credit limits on PayPal have REDUCED - NOT OK, because "reduce" requires an object.
Fill in the gaps with "decrease" or "reduce", using the verbs in the correct form. Write both verbs in cases where possible.
1. Over the same period the percentage has _________ from 27 per cent to 9 per cent.
2. The roar ___________ in volume.
3. We have been able ___________ our tax bill by 10%.
4. The population of the area has _________ radically.
5. The attorney managed ____________ the term of imprisonment.
6. The unemployment level has ______________.
7. The government managed to ____________ the unemployment level.
8. I've ________ the amount of chocolate I eat.
9. Unfortunaly, my academic performance has _______ this year