Regular verb: substitute - substituted - substituted
Simple form | V-ing form |
I could substitute you could substitute he could substitute we could substitute you could substitute they could substitute | I could be substituting you could be substituting he could be substituting we could be substituting you could be substituting they could be substituting |
Perfect | V-ing perfect |
I could have substituted you could have substituted he could have substituted we could have substituted you could have substituted they could have substituted | I could have been substituting you could have been substituting he could have been substituting we could have been substituting you could have been substituting they could have been substituting |
Simple form | V-ing form |
I couldn't substitute you couldn't substitute he couldn't substitute we couldn't substitute you couldn't substitute they couldn't substitute | I couldn't be substituting you couldn't be substituting he couldn't be substituting we couldn't be substituting you couldn't be substituting they couldn't be substituting |
Perfect | V-ing perfect |
I couldn't have substituted you couldn't have substituted he couldn't have substituted we couldn't have substituted you couldn't have substituted they couldn't have substituted | I couldn't have been substituting you couldn't have been substituting he couldn't have been substituting we couldn't have been substituting you couldn't have been substituting they couldn't have been substituting |
Simple form | V-ing form |
could I substitute? could you substitute? could he substitute? could we substitute? could you substitute? could they substitute? | could I be substituting? could you be substituting? could he be substituting? could we be substituting? could you be substituting? could they be substituting? |
Perfect | V-ing perfect |
could I have substituted? could you have substituted? could he have substituted? could we have substituted? could you have substituted? could they have substituted? | could I have been substituting? could you have been substituting? could he have been substituting? could we have been substituting? could you have been substituting? could they have been substituting? |
Simple form | V-ing form |
couldn't I substitute? couldn't you substitute? couldn't he substitute? couldn't we substitute? couldn't you substitute? couldn't they substitute? | couldn't I be substituting? couldn't you be substituting? couldn't he be substituting? couldn't we be substituting? couldn't you be substituting? couldn't they be substituting? |
Perfect | V-ing perfect |
couldn't I have substituted? couldn't you have substituted? couldn't he have substituted? couldn't we have substituted? couldn't you have substituted? couldn't they have substituted? | couldn't I have been substituting? couldn't you have been substituting? couldn't he have been substituting? couldn't we have been substituting? couldn't you have been substituting? couldn't they have been substituting? |