A Practical Guide to Tão and Tanto
[!related]
English uses "so" for almost everything: "I'm so tired," "There's so much traffic." Portuguese splits that into two words, tão and tanto. Getting the split right is one of the fastest ways to make your sentences sound less like you just memorized something from Google Translate.
Tão means "so" and pairs with qualities. Tanto means "so much" or "so many" and pairs with quantities.
Each one behaves differently from there.
Tão for Qualities
Tão describes how something is. It sits before an adjective or an adverb, and it never changes form, no matter what comes after it. Masculine, feminine,...