If you have the sound fu but not the character, here are the 4 characters read this way: 夫 (fū, husband, a grown man, laborer; the literary particle fú), 福 (fú, fortune, blessing, good luck), 富 (fù, rich, wealthy, abundant, to enrich), 父 (fù, father, male elder, household head). They split across 3 tones, so the tone is what separates them.