

Não sei a razão desta dor de cabeça.
Por que razão não vieste à aula ontem?
Ela teve as suas razões para sair mais cedo.
"a razão" is in the lesson "Head" (Level 44), along with 11 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.