

O meu filho tem cinco anos.
O teu filho anda na escola?
O filho do João mora em Lisboa.
"o filho" is in the lesson "Family 2" (Level 24), along with 13 other useful words. LinDuo has 180 topic lessons like this one, 2,380 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.