The phrase "endeavor to ensure" is correct and usable in written English. You can use it to express striving to guarantee something. For example, "We will endeavor to ensure that the procedures we set in place are fair for everyone.".
And I will endeavor to ensure that all voices that speak with respect are heard, including my own, no matter how difficult or controversial the message, as we struggle to build a different future in which all human rights are upheld.
Unfortunately, this vague process does nothing to calm the nerves of millions of high school students (who meet Ivy League criteria) and their parents (who endeavor to ensure their children's future social capital via an Ivy League degree) given the competitive landscape.
We secured collars with two rivets in an endeavor to ensure that premature collar loss did not occur, and relied on the weathering and deterioration of the collar leather to facilitate eventual collar failure and collar/transmitter shedding.
The researcher working with this population must be well aware of this, and must endeavor to ensure that patients truly understand the nature and potential outcomes of the trial before they agree to consent to participate.
Also, Roosevelt endeavored to ensure that more than half of the country was always on his side.
But according to several sources involved in his inaugural preparations, Trump has endeavored to ensure that his first day as commander-in-chief is marked by an unusual display of heavy military equipment.
"When companies and corporate insiders make statements, they must act responsibly, including endeavoring to ensure the statements are not false or misleading and do not omit information a reasonable investor would consider important in making an investment decision," he said in the statement.
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union