Quanti anni hai? is an Italian equivalent of the English phrase "How old are you?"
Specifically, the masculine interrogative quanti means "how many." The masculine noun anni means "years." The verb hai means "(informal singular you) are having, do have, have."
The pronunciation is "KWAHN-tee AHN-nee eye."*
*The sound is similar to that in the English noun "eye."
Quanti anni ho? is an Italian equivalent of the English phrase "How old am I?" The question translates literally into English as "How many years do I have?" The pronunciation will be "KWAN-tee AN-nee o" in Italian.
Settanta anni di età is an Italian equivalent of the English phrase "seventy years old." The phrase translates literally as "seventy years of age" in English. The pronunciation will be "set-TAN-ta AN-nee dee ey-TA" in Pisan Italian.
Ho ... anni is an Italian equivalent of the incomplete English phrase "I am ... years old." The number will be inserted between Ho ("I have") and anni ("years [old]"). The pronunciation will be "o AN-nee" in Pisan Italian.
Invecchiando is a literal Italian equivalent of the English phrase "getting old." The present participle in question translates additionally as "aging" and "maturing" in English. The pronunciation will be "EEN-vek-KYAN-do" in Pisan Italian.
Cinquantacinque anni d'età is an Italian equivalent of the English phrase "55 years old." The phrase translates literally as "fifty-five years of age" in English. The pronunciation will be "tcheen-KWAN-ta-TCHEEN-kwey AN-nee dey-TA" in Pisan Italian.
Ho sei anni is an Italian equivalent of the English phrase "I am six years old." The declaration translates literally as "I have six years" in English. The pronunciation will be "o sey AN-nee" in Pisan Italian.
Ho diciotto anni is an Italian equivalent of the English phrase "I am 18 years old." The declaration translated literally as "I have 18 years" in English. The pronunciation will be "o dee-TCHOT-to AN-nee" in Pisan Italian.
Ho quattro anni is an Italian equivalent of the English phrase "I am four years old." The declaration translates literally as "I have four years" in English. The pronunciation will be "o KWAT-tro AN-nee" in Pisan Italian.
Ho ventuno anni is an Italian equivalent of the English phrase "I am twenty-one (21) years old." The declarative statement literally translates into English by word order as "I have 21 years." The pronunciation will be "oh ven-TOO-no AN-nee" in Italian.
Ho quindici anni is an Italian equivalent of the English phrase "I am 15 years old." The declaration translates literally as "I have 15 years" in English. The pronunciation will be "o KWEEN-dee-tchee AN-nee" in Pisan Italian.
Per nonno is an Italian equivalent of the English phrase "to grandad." The prepositional phrase also translates as "for grandfather" in English. The pronunciation will be "per NON-no" in Italian.
Dopo di ciò is an Italian equivalent of the English phrase "after that." The prepositional phrase literally translates into English as "after of that." The pronunciation will be "DO-po dee tcho" in Italian.