You also have to take the rest of the sentence into account too. English has a lot of words which mean different things depending on how they're pronounced (or, from the other side, that you can't know which way to pronounce until you already know the meaning), e.g. bass, close, desert, does, dove, familiar, have, intimate, invalid, lead, lives, number, object, present, produce, read, refuse, sewer, sow, subject, tear, wind, wound.