Solutions :

3-letter words (1 point): 43

ERN; ERS; EST; ETH; EWT; HEN; HER; HES; HET; HEW; IOS; IRE; ISM; ISO; ITS; MIS; NET; NEW; NTH; ORE; ORS; ORT; OSE; REH; RES; RET; REV; RIT; SER; SET; SIM; SIR; SIS; SIT; SRI; TEN; TES; TEW; THE; TIS; VET; WEN; WET.

4-letter words (1 point): 63

ERNE; EROS; ERST; ETEN; ETHE; EWTS; HENT; HERN; HERO; HERS; HEST; HETE; HETS; HEWN; IRES; ISIT; MIST; MITT; NETE; NETS; NETT; NEWT; ORES; ORTS; REST; RETE; RETS; RISE; RITS; RITT; ROSE; ROST; SERS; SETT; SIRE; SIRS; SIST; SITS; SMIT; SORE; SORI; SORN; SORT; SRIS; STEN; STEW; STIM; STIR; TENT; TERN; THEN; THEW; TIRE; TIRO; TRES; TRET; TRIO; VERS; VERT; VEST; VETS; WENT; WETS.

5-letter words (2 points): 38

ENTER; ESTRO; ETHER; HENTS; HEROS; HETES; MITIS; MITRE; MITTS; NETES; NETTS; NEWTS; RESIT; RITTS; ROIST; ROSET; ROSIT; SETTS; SIRES; SORTS; STENT; STERN; STIRE; STIRS; TENTS; TERNE; TERTS; TIRES; TIROS; TREST; TRETS; TRIOS; TRIST; TROIS; VERSO; VERST; VERTS; WENTS.

6-letter words (3 points): 24

ENTERS; ENTIRE; ETHERS; HETERO; MITRES; MITTEN; NETHER; OSTENT; RESIST; RESITS; ROSITS; SISTER; SITTEN; SITTER; STENTS; STIRES; THESIS; TRIOSE; TRISTE; TSORIS; VERISM; VERIST; VERSTE; WETHER.

7-letter words (7 points): 10

ENTIRES; ENTRISM; ENTRIST; HEROISM; HETEROS; OSTENTS; SIROSET; SITTERS; SMITTEN; WETHERS.

8-letter words (11 points): 2

ETHERISM; ETHERIST.

9-letter words (11 points): 2

ENTERITIS; HETEROSIS.