頑皮的小男孩愛他的爸爸。

English Translation

The mischievous boy loves his dad.

Why is the pinyin “bà bɑ?” Is the ɑ a typo or does it have some extra meaning?

Without a tone mark, it means it’s a neutral tone. Some people consider it a fifth tone and others consider it toneless. Look up something along the lines of “Mandarin neutral tone” to read more about it :slight_smile: