affect1

Origin:

late Middle English (in the sense 'attack as a disease'): from French affecter or Latin affect- 'influenced, affected', from the verb afficere (see affect²)

Affect and effect are both verbs and nouns, but only effect is common as a noun, usually meaning ‘a result, consequence, impression, etc.’: my father’s warnings had no effect on my adventurousness. The noun affect is restricted almost entirely to psychology (see affect³). As verbs, they are used differently. Affect most commonly means ‘produce an effect on, influence’: smoking during pregnancy can affect the baby’s development. Affect also means ‘pretend to have or feel (something)’ (see affect²): she affected a concern for those who had lost their jobs. Effect means ‘bring about’: the negotiators effected an agreement despite many difficulties.