Affect And Effect
From 'Vocabulary' part of The ABC Of Plain Words by Sir E Gowers (1951)

Effect is both a noun and a verb. As a verb it means to bring about, to accomplish. As a noun it means primarily something caused or produced, a result, a consequence. Affect is only a verb its use as a noun is obsolete or technical. The most common meaning of affect is have an effect on. Thus we may say either "that does not affect my plans" or "that has no effect on my plans", and mean the same thing. But "my plans are affected" means almost the opposite of "my plans are effected". The second indicates accomplishment of the plans, the first an obstacle to their accomplishment.

Because affect is a colourless word it has won an undeserved popularity. It is of the class of factor, issue, involve —a word of broad meaning that saves a writer the trouble of close thought. It is a useful word in its place, but it should not be used from laziness. Do not say "the progress of the building has been affected by the weather", but prefer a more precise word, hindered, perhaps, or delayed or stopped.