Regex condition string contains English AND NOT Greek or vice versa (Greek and not English) only

Question

I am trying to build a regex in C# code that checks if an input text contains either Greek or English but not both at the same time like the following example:

Angela = true
Ανγκελα = true
AngeΛα = false
Αντζela = false

I have tried the following with no luck:

[a-zA-Z\s]?[α-ωΑ-Ω\s]
[a-zA-Z\s]|[α-ωΑ-Ω\s]

some more info

Answer 1

Taking into account the sample input provided in the question, you can use

^(?:[a-zA-Z]+|[α-ωΑ-Ω]+)$

Details

• ^ - start of string
• (?:[a-zA-Z]+|[α-ωΑ-Ω]+) - either one or more ASCII letters or one or more Greek letters
• $ - end of string.