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I'll be preascertaining you'll be preascertaining he'll be preascertaining we'll be preascertaining you'll be preascertaining they'll be preascertaining
Futur antérieur
I'll have preascertained you'll have preascertained he'll have preascertained we'll have preascertained you'll have preascertained they'll have preascertained
Futur antérieur continu
I'll have been preascertaining you'll have been preascertaining he'll have been preascertaining we'll have been preascertaining you'll have been preascertaining they'll have been preascertaining
I'd be preascertaining you'd be preascertaining he'd be preascertaining we'd be preascertaining you'd be preascertaining they'd be preascertaining
Passé
I'd have preascertained you'd have preascertained he'd have preascertained we'd have preascertained you'd have preascertained they'd have preascertained
Passé continu
I'd have been preascertaining you'd have been preascertaining he'd have been preascertaining we'd have been preascertaining you'd have been preascertaining they'd have been preascertaining