I've been extemporising you've been extemporising she's been extemporising we've been extemporising you've been extemporising they've been extemporising
I'll be extemporising you'll be extemporising she'll be extemporising we'll be extemporising you'll be extemporising they'll be extemporising
Future perfect
I'll have extemporised you'll have extemporised she'll have extemporised we'll have extemporised you'll have extemporised they'll have extemporised
Future perfect continuous
I'll have been extemporising you'll have been extemporising she'll have been extemporising we'll have been extemporising you'll have been extemporising they'll have been extemporising
I'd be extemporising you'd be extemporising she'd be extemporising we'd be extemporising you'd be extemporising they'd be extemporising
Past
I'd have extemporised you'd have extemporised she'd have extemporised we'd have extemporised you'd have extemporised they'd have extemporised
Past continuous
I'd have been extemporising you'd have been extemporising she'd have been extemporising we'd have been extemporising you'd have been extemporising they'd have been extemporising