if (in case that, or on condition that): if you try hard, you will succeed. If it rains, I will stay indoors.
whether (used to express a doubt or choice between alternatives): I couldn’t decide whether to go to the beach or stay home.
in case (used to introduce a condition that might happen): Take this umbrella in case it rains.
on condition that (only if): I will let you stay in this room on condition that you pay the rent on time.
provided that (on the condition that, as long as): We can go on a picnic, provided that the weather is nice.
assuming (to accept something as true without question or proof): Assuming the flight departs on time, we’ll arrive in Paris at 7 a.m.
whether or not (regardless of the condition, no matter if): I will go to the beach tomorrow whether or not it rains.
