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

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

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

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

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

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.

His persistent schoolboyism during meetings undermined his credibility.

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

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