Solutions :

3-letter words (1 point): 25

ANE; ANT; ARS; ART; EST; FEN; FES; ITA; ITS; NAT; NEF; QAT; QIS; RAN; RAT; SEI; SEN; SIT; TAN; TAR; TIE; TIS; TIT; WIS; WIT.

4-letter words (1 point): 32

ANES; ANTA; ANTI; ANTS; ARTI; ARTS; FEIS; FENT; FEST; ISIT; NATS; NEST; QATS; RANT; RATA; RATS; SENA; SENT; SIEN; SITS; STAR; STIE; TANE; TARA; TARS; TIES; TITI; TITS; TWIT; WISE; WIST; WITS.

5-letter words (2 points): 25

AARTI; ANTAR; ANTIS; ANTRA; ARTIS; FEIST; FENTS; NATIS; NEIST; RANTS; RATAN; SENTI; SENTS; SIENT; SITAR; STANE; STIES; SWIES; SWITS; TITAN; TITIS; TRANQ; TWIST; TWITS; WITAN.

6-letter words (3 points): 10

AARTIS; ANTARS; ARTIES; ARTIST; SEITAN; SIENTS; SITARS; STANES; TRANQS; WISENT.

7-letter words (7 points): 3

ARTIEST; ENTWIST; WISENTS.