English verb conjugation
COULD PRECHECK

Regular verb: precheck - prechecked - prechecked

Affirmation

Simple form	V-ing form
I could precheck you could precheck he could precheck we could precheck you could precheck they could precheck	I could be prechecking you could be prechecking he could be prechecking we could be prechecking you could be prechecking they could be prechecking
Perfect	V-ing perfect
I could have prechecked you could have prechecked he could have prechecked we could have prechecked you could have prechecked they could have prechecked	I could have been prechecking you could have been prechecking he could have been prechecking we could have been prechecking you could have been prechecking they could have been prechecking

Negation

Simple form	V-ing form
I couldn't precheck you couldn't precheck he couldn't precheck we couldn't precheck you couldn't precheck they couldn't precheck	I couldn't be prechecking you couldn't be prechecking he couldn't be prechecking we couldn't be prechecking you couldn't be prechecking they couldn't be prechecking
Perfect	V-ing perfect
I couldn't have prechecked you couldn't have prechecked he couldn't have prechecked we couldn't have prechecked you couldn't have prechecked they couldn't have prechecked	I couldn't have been prechecking you couldn't have been prechecking he couldn't have been prechecking we couldn't have been prechecking you couldn't have been prechecking they couldn't have been prechecking

Interrogative form

Simple form	V-ing form
could I precheck? could you precheck? could he precheck? could we precheck? could you precheck? could they precheck?	could I be prechecking? could you be prechecking? could he be prechecking? could we be prechecking? could you be prechecking? could they be prechecking?
Perfect	V-ing perfect
could I have prechecked? could you have prechecked? could he have prechecked? could we have prechecked? could you have prechecked? could they have prechecked?	could I have been prechecking? could you have been prechecking? could he have been prechecking? could we have been prechecking? could you have been prechecking? could they have been prechecking?

Interro-negative form

Simple form	V-ing form
couldn't I precheck? couldn't you precheck? couldn't he precheck? couldn't we precheck? couldn't you precheck? couldn't they precheck?	couldn't I be prechecking? couldn't you be prechecking? couldn't he be prechecking? couldn't we be prechecking? couldn't you be prechecking? couldn't they be prechecking?
Perfect	V-ing perfect
couldn't I have prechecked? couldn't you have prechecked? couldn't he have prechecked? couldn't we have prechecked? couldn't you have prechecked? couldn't they have prechecked?	couldn't I have been prechecking? couldn't you have been prechecking? couldn't he have been prechecking? couldn't we have been prechecking? couldn't you have been prechecking? couldn't they have been prechecking?