bachor in inglese:

Ona ma pięcioletniego brata.

Why does that irritating little brat ask so many stupid questions?

Mój brat jest wysoki.

a spoilt brat

‘she's been acting like a spoiled brat all evening

Thanks, I hear you've been taking care of my little brat of a brother.

40, 50, is a snot-nosed brat.