diff --git a/WetPancake/DataServices.fs b/WetPancake/DataServices.fs
index a18695f..73dfb3d 100644
--- a/WetPancake/DataServices.fs
+++ b/WetPancake/DataServices.fs
@@ -94,4 +94,16 @@
         |> ConcatToString
         |> ReplaceArtifact "  "
         |> TrimEnd [|' '|]
-        
\ No newline at end of file
+
+    let TextContainsValidEndToken (text: string) =
+        let result = text.Contains "." || text.Contains"!" || text.Contains "?"
+        match result with
+        | true -> true
+        | false -> failwith "The text does not contain a valid end token ('.', '!' and/or '?')."
+    (*
+        match text with
+        | text when (text.Contains".") -> true
+        | text.Contains "!" -> true
+        | text.Contains "?" -> true
+        | _ -> failwith "The text does not contain a valid end token ('.', '!' and/or '?')."
+        *)
diff --git a/WetPancake/Script.fsx b/WetPancake/Script.fsx
index 4e0c751..e874ed0 100644
--- a/WetPancake/Script.fsx
+++ b/WetPancake/Script.fsx
@@ -160,6 +160,12 @@ let dss_clean =
     |> RemoveArtefactSentences 6 // Change the no. of sentences to test.
 printfn "CLEANED TEXT: %s" dss_clean
 
+let dss_sentences3 = "This is a test setence?"
+let dss_validEndToken () =
+    let result = TextContainsValidEndToken dss_sentences3
+    result
+printfn "Valid End Token: %b" (dss_validEndToken())
+
 
 // Product Services (Pancake)
 let ps_files = Pancake.RequestAllTemplateFilesAsync ()