- your grandfather (at age 33, you’re unlikely to be a grandmother yourself)
- your uncle
- nephew, the son of a full sister or brother (if the nephew were the son of a half-sibling, you and he would share closer to 850 cM of DNA)
- your half-brother
Knowing the age of the match would help you decide between grandfather and uncle/nephew/half-sibling. However, if your match doesn’t provide his age and doesn’t respond to requests for additional information, AncestryDNA offers a tool you can use to further examine this relationship: Shared Matches.