She happens upon a hidden garden behind the old library every spring.

Happening upon a dusty photograph in the attic, Maria felt as if she had uncovered a family secret.

I happen upon an old bookstore tucked between two cafés and spend the afternoon browsing its dusty shelves.

She tried to improve upon the prototype's design before presenting it to the investors.

The new curriculum was built upon feedback from teachers and students.

The team is building upon last year's design to create a more sustainable product.

The servers were waiting upon the guests with trays of hors d'oeuvres during the reception.

The butler waits upon the ambassador with quiet efficiency.

She waited upon every guest with a warm smile during the reception.

She managed to furnish her tiny apartment upon a sixpence, finding bargains at every corner.