The phrase "assuring substantial" is correct and usable in written English.
It can be used in contexts where you want to convey the idea of providing a significant level of assurance or guarantee regarding something.
Example: "The company is committed to assuring substantial improvements in customer satisfaction through its new policies."
Alternatives: "providing significant" or "ensuring considerable".
Laid out in 1825 by Gen. Simon Perkins, commissioner of the Ohio Canal Fund, the town was assured substantial growth by the completion of the Ohio and Erie Canal in 1827 and of the Pennsylvania and Ohio Canal in 1840, linking it with Pittsburgh.
In addition, I'm assured that substantial measures to address "the huge issue" of road congestion can be expected soon.
Joseph signed an alliance giving her a free hand for her far-reaching plans and the conquest of Constantinople and the Dardanelles and assuring Austria of substantial territorial gains.
In 1996, as NATO prepared to admit Eastern Europe, it set up a formal relationship with Russia, assuring it that no nukes and no "substantial combat forces" would be placed close to its border.
That must include assuring that all German residents, including the country's substantial Muslim community, are guaranteed equal protection and encouraged to cooperate with his ministry in combating extremism.
Though collected by multiple abstractors, the results show high sensitivity and specificity and substantial to excellent inter- and intra-rater agreement, assuring confidence in the use of chart abstraction for evaluating the ACP.
This year, the company's CEO, Bob Dudley, spoke with unbridled optimism about the future market for his company's energy products, assuring his audience that the global supply of fossil fuels would remain substantial for years to come.
A month after issuing its first profits warning in June – at which point the company had assured investors it had substantial headroom in its bank borrowing facilities – Connaught released a further trading update informing investors the business now had "an urgent requirement for additional funds to meet the current and ongoing needs of the business".
The backlash to this was substantial and Instagram seem to recognise this in the latest announcement, assuring users that "As always, you own your own photos and videos".
Studies assuring the effectiveness of universal screening in decreasing MRSA prevalence showed that there was a substantial reduction in MRSA infections with screening and decolonization [ 6, 51].
