“Only when” is a conjunction that adds specificity to conditions by restricting the circumstances in which a particular outcome can occur. Unlike “if” or “provided that,” which can be more general, “only when” emphasizes a critical or exclusive condition that must be met for a specific result.

For example, consider the following sentences:

– If it rains, I will bring an umbrella. (General statement)

– Provided that it rains, I will bring an umbrella. (Conditional statement)

– Only when it rains heavily, I will bring an umbrella. (Specific and exclusive condition)

In this case, “only when” highlights that the action of bringing an umbrella is contingent upon the heavy rain, making the condition more specific and precise. It helps clarify the exact time or circumstances necessary for the outcome to be true or valid, thereby adding a higher degree of specificity compared to other conjunctions.

By using “only when,” the speaker explicitly states the unique situation under which the action will take place, offering a clear and definitive condition that must be fulfilled for the stated consequence to occur.