If only if is often used as a conditional phrase that expresses a wish or desire for a certain outcome. However, there are several synonyms for if only if that can be used interchangeably. For example, the phrase "provided that" can be used instead of if only if to express a condition that must be met in order for something to happen. Other synonyms for if only if include "in the event that," "assuming that," and "on the condition that." These phrases all serve the same purpose of expressing a condition or contingency that must occur for a desired outcome to be achieved.