For 2019 if they are 24 or older and have $4,200 or more income you can not claim them. What do you mean file his own for the 4,000?
If anyone only has W2 income less than 12,200 they don't have to file a return except to get back any withholding taken out.
Do you need to file a return?
https://ttlc.intuit.com/community/filing-and-paying-taxes/help/do-i-need-to-file-a-federal-return-th...
