When expressing an effort to achieve something, there are numerous synonyms for the phrase "attempt to." These include endeavors, tries, efforts, undertakings, ventures, experiments, assays, essays, tests, and trials. Each of these words serves to convey slightly different nuances and degrees of intensity in the attempt, from a simple effort to a more significant, purposeful undertaking. Using synonyms for "attempt to" can add depth and variety to your writing and provide readers with a clearer picture of the degree of effort you're describing. Whatever synonym you choose, make sure it accurately reflects the particular type of attempt you're describing.