diff --git a/ps-grammar/confirm/confirm.jsgf b/ps-grammar/confirm/confirm.jsgf
index 246e8bf41fc6e13d20c3a0a92c7dd0961232c94e..5e90506a9c4fa9ce66980c4c44c34f0aff8d015d 100644
--- a/ps-grammar/confirm/confirm.jsgf
+++ b/ps-grammar/confirm/confirm.jsgf
@@ -1,5 +1,10 @@
 #JSGF V1.0;
 grammar ToBI_confirm;
 public <confirm> = <confirm_yes> | <confirm_no>;
-<confirm_yes> = (tobi yes);
-<confirm_no> = (tobi no); 
+
+<confirm_yes> = <robot> <yes_words>;
+<confirm_no> = <robot> <no_words>; 
+
+<yes_words> = (yes | confirmed);
+<no_words> = (no);
+<robot> = (tobi | robot | biron);