Conditional conjunctions

Common conditional conjunctions:

Conditional marker	Category	Example	Basic force
as long as	subordinator	You can stay as long as you behave.	condition / requirement
assuming (that)	preposition	Assuming that he agrees, we’ll proceed.	hypothetical assumption
even if	subordinator	Even if he agrees, we may refuse.	concessive condition
if	subordinator	If he agrees, we’ll proceed.	condition
if and only if	subordinator	The condition holds if and only if X is true.	necessary + sufficient condition
in case	preposition	Take an umbrella in case it rains.	precautionary condition
in the event that	PP	In the event that he agrees, we’ll proceed.	contingency
on condition that	PP	We’ll agree on condition that they pay.	explicit requirement
only if	subordinator	We’ll proceed only if he agrees.	necessary condition
provided (that)	preposition	You can stay provided that you behave.	condition / requirement
providing (that)	preposition	You can stay providing that you behave.	condition / requirement
should	modal auxiliary	Should he agree, we’ll proceed.	remote / contingent condition
so long as	subordinator	You can stay so long as you behave.	condition / requirement
suppose (that)	verb	Suppose that he agrees. What then?	hypothetical assumption
supposing (that)	preposition	Supposing that he agrees, what then?	hypothetical assumption
unless	subordinator	Unless he agrees, we’ll proceed without him.	negative condition

Note

Conjunction as a broader term, not a CGEL category