Conjugation of verb "To cost"
Present Simple Continuous
Negative
He/She/It wasn't costing.
Present Perfect Continuous
Affirmative
He/She/It's been costing.
Negative
You haven't been costing.
He/She/It hasn't been costing.
You haven't been costing.
They haven't been costing.
Interrogative
Has he/she/it been costing?
Affirmative
He/She/It'd been costing.
Negative
He/She/It hadn't been costing.
They hadn't been costing.
Interrogative
Had he/she/it been costing?
Negative
He/She/It won't have cost.
Interrogative
Will he/she/it have cost?
Negative
He/She/It wouldn't have cost.
Interrogative
Would he/she/it have cost?