"They study the Industrial Revolution."

Translation: Eles estudam a Revolução Industrial.

[jeanna4]

I guess I just don't understand feminine v. masculine if words end in -ao. Are they always feminine?

[liriko77]

not always, but most of the time. like the word "perdão" is masculine.

[4oYBIxtO]

One rule is that words which end in "tion" in English are feminine in Portuguese.

[tommg]

If I'm not mistaken, the vast majority of words ending in '-ão' conform to the following rules regarding gender: if the ending is '-ção' or '-são', it's feminine; otherwise it's masculine.