3 формы глагола sing

Ответ от Stanislawa[гуру]
be,was,were,been;
take,took,taken;
have,had,had;
tell,told,told;
go,went,gone;
fly,flied,flied;
sing,sang,sung;
see,saw,seen;
win,won,won;
make,made,made;
buy,bought,bought;
sit,sat,sat