What is was thinking about in Portuguese?

The phrase "what was thinking about" in Portuguese can be translated in a few ways, depending on the context and the desired level of formality. Here are some options:

Formal:

* O que estava pensando? (What were you thinking?)

* Em que estava pensando? (What were you thinking about?)

* Sobre o que estava pensando? (What were you thinking about?)

Informal:

* No que você tava pensando? (What were you thinking about?)

* O que você tava pensando? (What were you thinking?)

More idiomatic:

* O que te passou pela cabeça? (What went through your head?)

* O que te deu na cabeça? (What came into your head?) (This last one is more informal and could be used when someone did something strange or unexpected.)

It's important to choose the translation that best suits the situation and the level of formality. For example, if you are talking to a friend, you could use the more informal options. If you are talking to someone in a professional setting, you would use the more formal options.