He flashed a schoolboy grin before tripping over his own backpack in front of everyone.

The schoolboy carried a stack of textbooks across the rainy playground.

The schoolboys lined up quietly before the assembly, clutching their notebooks.

Forgetting to save the file before closing was a schoolboy error that cost the team hours of work.

The report was riddled with schoolboy errors that undermined the team's credibility.

Despite the instructor's warnings, the cadets proudly showed off their schoolboy knots after learning the basic binding technique.

He learned to tie the schoolboy knot before his first day at work.

He grinned schoolboyishly when he realized he'd found the missing key.

His schoolboyish grin and impulsive excuses made it hard for colleagues to take him seriously.

His persistent schoolboyism during meetings undermined his credibility.