他今年73岁怎么说英语

To say "he is 73 years old" in English, you can say "He is 73 years old." or "He is seventy-three years old." If you want to specify that the person is 73 years old this year, you can say "He is 73 years old this year." or "He is seventy-three years old in 2021." Please note that the year 2021 should be replaced with the current year if it is not 2021.