I forgot to add the english dialogs to the distribution.
You can download them by anonymous FTP from hatutu.imag.fr :
the file pub/patch/en-dialog.tar.gz should be ungzipped
and untarred from the root.
I will upload a new version with the english dialog this
Don't forget to modify /usr/local/thot/bin/thot to change
LANG to en_US or to set it as an environment variable.