Can I add my full time college student son's summer internship wages of $8687 (he received a W-2) to my return or does he need to file a separate tax return for himself?

My son was 19 years old in 2018 and a full time college student. During the summer of 2018 he had an internship for which he received wages of $8687 and received a W-2. Federal, Social Security, Medicare and Virginia State (the internship was in Virginia, where we live) taxes were withheld. My son did not have any other income in 2018. 

1) Can I add his W-2 to our return (married parents filing jointly) or does my son need to file a separate return for himself?

2) If he needs to file a separate return for himself, can I still claim him as a dependent?  We paid more than half of his living expense, tuition, etc.