This is the 6th most frequent Portuguese word.
no
"In the" (contraction of "em" + "o").
Here, 'no' is a contraction of 'em' + 'o' (in the + masculine singular noun), indicating location.
Eu vi um pássaro no jardim.
I saw a bird in the garden.
Here, 'no' is 'em' + 'o' (in/at the + masculine singular noun), indicating location again, but for a specific venue.
Antes de ir para o trabalho, ele tomou café no café da esquina.
Before going to work, he had coffee at the coffee shop on the corner.
In this case, 'no' combines 'em' + 'o' (in/on the + masculine singular noun), indicating consideration or thought about a concept.