diff --git a/ps-grammar/demoChallenge/commands.jsgf b/ps-grammar/demoChallenge/commands.jsgf
index e629d0a19640822f5e72fc47021c0b8cc632ad52..2dce336a5c72f710b9a017b97ae681774d4b183a 100644
--- a/ps-grammar/demoChallenge/commands.jsgf
+++ b/ps-grammar/demoChallenge/commands.jsgf
@@ -5,6 +5,6 @@ public <statement> = [tobi] [please] <command> [please] [tobi];
 <command> =  <mapping> | <clean> | <party> | <teach>;
 <clean> = (clean up) | (start cleaning);
 <mapping> = ( start mapping );
-<party> = ( [the] party starts) | (party beginning);
+<party> = ( [the] party starts) | (party beginning) | (party starting)  | (lets start the party);
 <teach> = ( (this is [a | an | the] ) | ( these are [the] ) ) <object>;
 <object> = trashbin;