I can throb you can throb she can throb we can throb you can throb they can throb
V-ing form
I can be throbbing you can be throbbing she can be throbbing we can be throbbing you can be throbbing they can be throbbing
Perfect
I can have throbbed you can have throbbed she can have throbbed we can have throbbed you can have throbbed they can have throbbed
V-ing perfect
I can have been throbbing you can have been throbbing she can have been throbbing we can have been throbbing you can have been throbbing they can have been throbbing
Negation
Simple form
I cannot throb you cannot throb she cannot throb we cannot throb you cannot throb they cannot throb
V-ing form
I cannot be throbbing you cannot be throbbing she cannot be throbbing we cannot be throbbing you cannot be throbbing they cannot be throbbing
Perfect
I cannot have throbbed you cannot have throbbed she cannot have throbbed we cannot have throbbed you cannot have throbbed they cannot have throbbed
V-ing perfect
I cannot have been throbbing you cannot have been throbbing she cannot have been throbbing we cannot have been throbbing you cannot have been throbbing they cannot have been throbbing
Interrogative form
Simple form
can I throb? can you throb? can she throb? can we throb? can you throb? can they throb?
V-ing form
can I be throbbing? can you be throbbing? can she be throbbing? can we be throbbing? can you be throbbing? can they be throbbing?
Perfect
can I have throbbed? can you have throbbed? can she have throbbed? can we have throbbed? can you have throbbed? can they have throbbed?
V-ing perfect
can I have been throbbing? can you have been throbbing? can she have been throbbing? can we have been throbbing? can you have been throbbing? can they have been throbbing?
Interro-negative form
Simple form
can I not throb? can you not throb? can she not throb? can we not throb? can you not throb? can they not throb?
V-ing form
can I not be throbbing? can you not be throbbing? can she not be throbbing? can we not be throbbing? can you not be throbbing? can they not be throbbing?
Perfect
can I not have throbbed? can you not have throbbed? can she not have throbbed? can we not have throbbed? can you not have throbbed? can they not have throbbed?
V-ing perfect
can I not have been throbbing? can you not have been throbbing? can she not have been throbbing? can we not have been throbbing? can you not have been throbbing? can they not have been throbbing?