Songs(to sing.) Pr.s. - + ? Past s. + - ? Fut.s. +-? Pr.Cont. +-? Past Count. -+? Fut.Cont.-+? Pr. Perf +-? Past perf +-? Fut perf +-? Pr.perf.cont

I sing songs I sang songs I will sing songs I'm singing songs I was singing songs l'll singing songs I have sung I had sung I'll have sung I have been singing