Qual è la differenza tra only if e as long as ?Sentiti libero di rispondere con un esempio.

This is a bit tricky. They both mean basically the same thing but are also quite different.

Only if is more defined and implies there is an ultimatum on something and it cannot happen unless there is something else involved for example "you can have ice cream, only if you finish dinner". This would mean it are not allowed to eat ice cream at all until dinner is finished.

As long as is a bit different and is more causal. "As long as you eat dinner you can have ice cream". They mean the same thing but one is more authoritative and final. A lot of the time if someone sad as long as they often won't follow through and are not that serious. Only if is very final and seems more urgent and important.