This is the 26th most frequent Portuguese word.
em
The Portuguese word "em" means "in," "on," or "at" in English, indicating location or time.
Here, 'em' indicates location, showing where the speaker is.
Eu estou em casa.
I am at home.
Here, 'em' specifies where the book was placed, indicating physical placement.
Ele colocou o livro em cima da mesa.
He placed the book on top of the table.
Here, 'em' is used in a figurative sense to show what the subject is thinking about.