guaranteed
v.v. to promise that something will happen or be true. You use this when you want to make someone feel certain about a result.
v. to provide a formal assurance or promise that certain conditions will be fulfilled. Transitive; often followed by a direct object or a 'that' clause.
The company guaranteed that the repairs would be finished by Friday.
The new law guaranteed every citizen the right to access clean drinking water regardless of their income.
While the contract guaranteed a minimum return on the investment, it could not protect the shareholders against a total collapse of the global market.
The verb is transitive and frequently takes a 'that' clause or a double object construction.
I guarantee you for a good timeI guarantee you a good timeThe verb is transitive and does not require the preposition 'for' when followed by an object.