The answer is simple: we learn about them and get to understand how to use them. Your dictionary is sufficient, whether you use a PC-based version, an online service, or a traditional printed copy. As a communicator, resolve to seek out and appreciate where the potential word traps may lie.
Let's define the differences between "affect" and "effect" now:
- Affect is a cause. Affect means to influence or change some thing or situation. For example: "How will the takeover affect us?"
- Effect is a result of what has happened. For example: "The effect of the takeover means that several new opportunities are now open to us."
However, the word "effect" can also be used as a verb (action word). Here's an example:
- "To effect a good result ..."
Key tip: nevertheless, I suggest you avoid using "effect" as a verb. Why? Such writing can be seen as pompous, ambiguous, old fashioned, clumsy. Usually, a better, simpler and more accurate alternative word choice is most likely available after a few seconds research with a thesaurus or dictionary.
For example, to "clean up" the previous example above, we could simply rewrite our sentence to read:
- "To ensure a good result ..."