Emphasizes the cause of an event not happening or a situation being different. We wouldn't have discovered the error if it wasn't for your attention to detail.
Pro Tip 2/3
Counterfactual Thinking
Used for imagining a different outcome in a hypothetical situation. If it weren't for the rain, we could have had the picnic.
Pro Tip 3/3
Gratitude Expression
Commonly used to express thankfulness for someone's actions or presence. If it weren't for your help, I wouldn't have finished the project on time.