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