How can you tell if an ancestor from Czechoslovakia is Sudeten German or Czech ethnically?

[Sehnsucht]

My great grandmother came from Stipton, Czechoslovakia. How can I discern whether she was a Sudeten German or ethnically Czech?

[Nehellenia]

What's her surname or her ancestral surnames? If she is a direct mitochondrial maternal grandma, you may be able to find out through genetic admixture also.

[CordedWhelp]

What's her surname or her ancestral surnames? If she is a direct mitochondrial maternal grandma, you may be able to find out through genetic admixture also.

In this situation, the ethnicity of the surname might not be the end-all-be-all. One of my great grandfathers came from a town in what is now Belarus, but had a Polish surname and that side of my family was only ever described as being "Polish". I don't guess, however, that many ethnic Poles migrated there, but Poles there are culturally Polonized Belorussians due to the once great Polish-Lithuanian commonwealth.

That being said, I'm not an expert on this topic and this is a different thing altogether. a population transplant could have happened?

[Nehellenia]

In this situation, the ethnicity of the surname might not be the end-all-be-all. One of my great grandfathers came from a town in what is now Belarus, but had a Polish surname and that side of my family was only ever described as being "Polish". I don't guess, however, that many ethnic Poles migrated there, but Poles there are culturally Polonized Belorussians due to the once great Polish-Lithuanian commonwealth.

That being said, I'm not an expert on this topic and this is a different thing altogether. a population transplant could have happened?

Yeah, i've heard of that as well too.. I know Lithuanians/Latvians with Russified and Polonised surnames but still Baltic.
I would believe though for Sudeten Germans, they are ethnicity mixed with both for sure.

[Windischer]

surname may help but not always.

[Mikula]

My great grandmother came from Stipton, Czechoslovakia. How can I discern whether she was a Sudeten German or ethnically Czech?

Lastname is not a key-word for the ethnicity, here. A lot of Czechs had and have lastnames of German origin and vice versa (due the mixed marriages during the history).
Nevertheless, census registers dated 1900 says that in Stipton (Wienau) (https://cs.wikipedia.org/wiki/%C5%A0tipto%C5%88)lived 502 German speaking and just 2 Czech speaking dwellers.

[Mikula]

Generally, if i will find census record of your ancestor, there will be written his/her native language, as well as another interesting data like religion, literacy, occupation, etc.

Another interesting source could be school records.

[TheMaestro]

Generally, if i will find census record of your ancestor, there will be written his/her native language, as well as another interesting data like religion, literacy, occupation, etc.

Another interesting source could be school records.

Je to dosť pravdepodobne že to boli Germáni. Ale týto ludia čo žili na hraniciach sa asimilovali vždy najviac.

[rothaer]

Lastname is not a key-word for the ethnicity, here. A lot of Czechs had and have lastnames of German origin and vice versa (due the mixed marriages during the history).
Nevertheless, census registers dated 1900 says that in Stipton (Wienau) (https://cs.wikipedia.org/wiki/%C5%A0tipto%C5%88)lived 502 German speaking and just 2 Czech speaking dwellers.

This is they key, as well as the fact that it's simply located in the contigous German settled area.

Regardless of this first names are far better to determine the ethnicity than are last names in a German-Czech context.

Btw, Wienau (yellow marker) is pretty close to all of Adolf Hitler's ancestral locations (blue markers), see pic.

https://i.imgur.com/ZexYPk7.jpg