I'll be retaining you'll be retaining he'll be retaining we'll be retaining you'll be retaining they'll be retaining
Future perfect
I'll have retained you'll have retained he'll have retained we'll have retained you'll have retained they'll have retained
Future perfect continuous
I'll have been retaining you'll have been retaining he'll have been retaining we'll have been retaining you'll have been retaining they'll have been retaining
I'd be retaining you'd be retaining he'd be retaining we'd be retaining you'd be retaining they'd be retaining
Past
I'd have retained you'd have retained he'd have retained we'd have retained you'd have retained they'd have retained
Past continuous
I'd have been retaining you'd have been retaining he'd have been retaining we'd have been retaining you'd have been retaining they'd have been retaining