affect / effect
One is what you do. One is what happens. You have a 50% success rate.
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Wrong: How will this effect the schedule?
Right: How will this affect the schedule?
It’s doing something to the schedule. Verb, so affect.
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Wrong: The affect was immediate.
Right: The effect was immediate.
The result. Noun, so effect.
The mnemonic
Affect is an Action. Effect is the End result.
Or: if you can put the in front of it, you want effect. The effect. You cannot say the affect in ordinary usage.
The exceptions nobody needs but everyone cites
Effect can be a verb meaning to bring about: to effect change. It’s formal, it’s rare, and it means something different from affect change—which isn’t a phrase.
Affect can be a noun in psychology, meaning observable emotion: flat affect. If you’re not writing a clinical note, this isn’t you.
Both exist. Neither is what you meant. Use the mnemonic.
Now go fix the sentence you were writing.