I'll be narrowing you'll be narrowing he'll be narrowing we'll be narrowing you'll be narrowing they'll be narrowing
Future perfect
I'll have narrowed you'll have narrowed he'll have narrowed we'll have narrowed you'll have narrowed they'll have narrowed
Future perfect continuous
I'll have been narrowing you'll have been narrowing he'll have been narrowing we'll have been narrowing you'll have been narrowing they'll have been narrowing
I'd be narrowing you'd be narrowing he'd be narrowing we'd be narrowing you'd be narrowing they'd be narrowing
Past
I'd have narrowed you'd have narrowed he'd have narrowed we'd have narrowed you'd have narrowed they'd have narrowed
Past continuous
I'd have been narrowing you'd have been narrowing he'd have been narrowing we'd have been narrowing you'd have been narrowing they'd have been narrowing