can=poate(la fel pt toate persoanele)
can't = nu poate (la fel pt toate persoanele)
was = am fost,a fost -folosit pt pers 1 si 3 singular
were= a fi la trecut dar pt restul persoanelor(2sg,1pl,2pl,3pl)
could= putea (este can la trecut)
couldn't=nu putea (este can't la trecut )