I could welcome you could welcome he could welcome we could welcome you could welcome they could welcome
V-ing form
I could be welcoming you could be welcoming he could be welcoming we could be welcoming you could be welcoming they could be welcoming
Perfect
I could have welcomed you could have welcomed he could have welcomed we could have welcomed you could have welcomed they could have welcomed
V-ing perfect
I could have been welcoming you could have been welcoming he could have been welcoming we could have been welcoming you could have been welcoming they could have been welcoming
Negation
Simple form
I couldn't welcome you couldn't welcome he couldn't welcome we couldn't welcome you couldn't welcome they couldn't welcome
V-ing form
I couldn't be welcoming you couldn't be welcoming he couldn't be welcoming we couldn't be welcoming you couldn't be welcoming they couldn't be welcoming
Perfect
I couldn't have welcomed you couldn't have welcomed he couldn't have welcomed we couldn't have welcomed you couldn't have welcomed they couldn't have welcomed
V-ing perfect
I couldn't have been welcoming you couldn't have been welcoming he couldn't have been welcoming we couldn't have been welcoming you couldn't have been welcoming they couldn't have been welcoming
Interrogative form
Simple form
could I welcome? could you welcome? could he welcome? could we welcome? could you welcome? could they welcome?
V-ing form
could I be welcoming? could you be welcoming? could he be welcoming? could we be welcoming? could you be welcoming? could they be welcoming?
Perfect
could I have welcomed? could you have welcomed? could he have welcomed? could we have welcomed? could you have welcomed? could they have welcomed?
V-ing perfect
could I have been welcoming? could you have been welcoming? could he have been welcoming? could we have been welcoming? could you have been welcoming? could they have been welcoming?
Interro-negative form
Simple form
couldn't I welcome? couldn't you welcome? couldn't he welcome? couldn't we welcome? couldn't you welcome? couldn't they welcome?
V-ing form
couldn't I be welcoming? couldn't you be welcoming? couldn't he be welcoming? couldn't we be welcoming? couldn't you be welcoming? couldn't they be welcoming?
Perfect
couldn't I have welcomed? couldn't you have welcomed? couldn't he have welcomed? couldn't we have welcomed? couldn't you have welcomed? couldn't they have welcomed?
V-ing perfect
couldn't I have been welcoming? couldn't you have been welcoming? couldn't he have been welcoming? couldn't we have been welcoming? couldn't you have been welcoming? couldn't they have been welcoming?