Many practitioners of the English language struggle with word pairs that are seemingly interchangeable, and may just be so in some exceptional cases, but mostly there is a clear distinction between the correct use, and usage which will create grammatical turmoil.
Today’s words are prevent and avoid.
The way I see it is the following: Avoid is used when a situation exists and something small needs to be done to get out of the situation or better manage it. Prevent presents a situation where a much more calculating action is required to change an outcome.
Simply put Avoid = stay clear from; keep away from; keep out of the way of someone or something; refrain from
Prevent = keep from happening or arising; stop (someone, something) from doing (something)
So for example, you can avoid sex by being cold and unresponsive to your partner. But to prevent pregnancy you would need to be on some kind of prophylactic. Thus your action in the ‘prevent’ case is far more calculating and conscious.
In another example, you can avoid paying tax, but to prevent prosecution from the tax authority, you would have to ensure that your documents could support the figures you have shown to avoid tax.
Again you can see, ‘avoiding’ is what you do when you go about your way, preventing requires a monitored audit of how you will defend your position should the need arise.
Goodman writes on an English forum site:
“I have tried to think of a way to verbally distinguish the difference of [avoid] and [prevent] and I seem to have come up short because they are so similar and in some cases we can switch one for the other, but it’s context dependent. We can’t, however, use them interchangeably as a rule.
Prevent heat stroke
“For instance, I can say, to avoid the morning rush hour traffic, I usually leave my house an hour early. In this context, prevent is a misfit. However, if I say “to prevent heat stroke on hot summer days, drink plenty of water and stay out of the sun”. In this context “avoid” also seems to work just fine.
I really can’t come up with a set of rules. May be the gurus can help.”
And here I disagree with Goodman. I don’t believe you can prevent heat stroke, any more than you can prevent a snow storm … it’s just one of those things, but I do believe you could avoid the sun.
But like Goodman says, and this applies to many, many alternatives in the English language, use the context to see if it fits.
As always, your feedback is most welcome.