Final answer:
John is currently 58 years old.
Step-by-step explanation:
To find out John's current age, we need to subtract the number of years mentioned in the question from the current year. Since John was 39 years old 19 years ago, we can calculate his current age as follows:
Current age = Age 19 years ago + 19
Current age = 39 + 19 = 58
Therefore, John is currently 58 years old.