The core idea of this root was:
apart, separated, by oneself
It’s the origin of English asunder as well as the imports sans (without) and sin (without) as in chili sin carne.
On the German side, we have two very important offspring – sich and sondern.
Is selbe the same as selber? With selbe i had been told it was a demonstrative pronoun and does not exist on its own but as a suffix such as dasselbe. Is this right, can you put me right please.
Yeah, what you learned is correct.
“dasselbe, dieselbe,…” are pronouns and “selbe” does not exist by itself.
However, many Germans will write “das selbe” just like they write “das gleiche”.
Officially, this is incorrect, because “dasselbe” is a pronoun while “das gleiche” is an adjective with an article used as a noun.
As for “selber”… that can technically also be used as a pronoun, I forgot to add that meaning, but only as a subject and it’s really really really rare.