could grade
Verbo regular: grade - graded- graded

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could grade
you could grade
he could grade
we could grade
you could grade
they could grade 	I could be grading
you could be grading
he could be grading
we could be grading
you could be grading
they could be grading	I could have graded
you could have graded
he could have graded
we could have graded
you could have graded
they could have graded	I could have been grading
you could have been grading
he could have been grading
we could have been grading
you could have been grading
they could have been grading	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not grade
you could not grade
he could not grade
we could not grade
you could not grade
they could not grade 	I could not be grading
you could not be grading
he could not be grading
we could not be grading
you could not be grading
they could not be grading	I could not have graded
you could not have graded
he could not have graded
we could not have graded
you could not have graded
they could not have graded	I could not have been grading
you could not have been grading
he could not have been grading
we could not have been grading
you could not have been grading
they could not have been grading	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I grade?
could you grade?
could he grade?
could we grade?
could you grade?
could they grade? 	could I be grading?
could you be grading?
could he be grading?
could we be grading?
could you be grading?
could they be grading? 	could I have graded?
could you have graded?
could he have graded?
could we have graded?
could you have graded?
could they have graded? 	could I have been grading?
could you have been grading?
could he have been grading?
could we have been grading?
could you have been grading?
could they have been grading? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not grade?
could you not grade?
could he not grade?
could we not grade?
could you not grade?
could they not grade? 	could I not be grading?
could you not be grading?
could he not be grading?
could we not be grading?
could you not be grading?
could they not be grading? 	could I not have graded?
could you not have graded?
could he not have graded?
could we not have graded?
could you not have graded?
could they not have graded? 	could I not have been grading?
could you not have been grading?
could he not have been grading?
could we not have been grading?
could you not have been grading?
could they not have been grading?