quel = comes before most masculine singular nouns that begin with a consonant. The exception is those masculine nouns beginning with ps, gn, z, or s followed by a consonant. Quel ragazzo viene sempre in ritardo. = That boy always comes late. quello = comes before a masculine singular nouns beginning with ps, gn, z, or s followed by a consonant. Compriamo quello specchio. = Let's buy that mirror. quell' = comes before all masculine singular nouns beginning with a vowel. Quell'uomo parla molto. = That man talks a lot. quella = comes before all femine singular nouns that begin with a consonant. Il presidente abita in quella casa. = The president lives in that house. quell' = comes before all femine singular nouns that begin with a vowel. Quell'arancia non e' buona. = That orange is not good. quei = is the plural of quel and comes before most masculine plural nouns that begin with a consonant. The exception is those masculine nouns beginning with ps, gn, z, or s followed by a consonant. Quei treni vanno a Milano. = Those trains go to Milan. quegli = is the plural of both quello and quell' and comes before all masculine plural nouns that begin with a vowel, or those that begin with ps, gn, z, or s followed by a consonant. Quegli studenti sono bravi. = Those students are good. quelle = is the plural of both quella and quell' and comes before any femine plural noun. Quelle famiglie non capiscono italiano. = Those families do not understand Italian.