As Jimmy says, effect is a noun, affect is a verb. What is the effect of tax deductions on contract employees? = noun How do deductions affect contract employees? = verb There is also a verb 'to effect' which means to make something happen (eg to effect a change). However, this is relatively unusual, and in most cases the word you will need is one of the two above - effect (noun) or affect (verb). And yes, as Jimmy says, most native speakers don't know the difference!

This is a good question. Many natives don't even know the difference! Effect is a noun; affect is a verb. Effect of tax deductions on contract employees is correct.

Thanks for this fromtion