Breakdown of O aluno compra um caderno.
o aluno
the student (m)
um
a / an / some (all forms)
o caderno
the notebook
comprar
to buy
Questions & Answers about O aluno compra um caderno.
How do we know to use compra instead of another form of the verb?
Could compra also mean "is buying"?
Yes! In Portuguese, the simple present tense often covers both actions happening generally and actions happening right now. So, O aluno compra translates to both "The student buys" and "The student is buying". You do not need to add an extra word for "is".
How can I tell if this student is male or female?
Does um caderno mean "a notebook" or "one notebook"?
It can mean either one. The Portuguese word um acts as both the masculine indefinite article ("a" or "an") and the number one. The exact meaning usually depends on the context, but here "a notebook" is the most natural translation.