unless / as long as / provided that

Rule

Rule

• • unless introduces a condition that must not happen for something else to happen.
  • as long as means something will happen if another condition continues.
  • provided that means something will happen if a condition is met.

Usage

• • We use unless to say something will not happen if another thing happens.
  • We use as long as to say something will happen as long as another condition is true.
  • We use provided that to say something will happen if another condition is met.

Examples

• I won't go to the party unless you go with me.
• You can borrow my car as long as you return it by tomorrow.
• I'll help you provided that you help me with my project.
• Unless it rains, we'll have a picnic.
• As long as you have your passport, you can travel.
• Provided that you study hard, you'll pass the exam.

Common Mistakes

• Wrong: I won't go unless you will go with me. Correct: I won't go unless you go with me.
• Wrong: I'll help you provided you help me. Correct: I'll help you provided that you help me.
• Wrong: We will go as long as it not rains. Correct: We will go as long as it doesn't rain.

Tip