Learn Portuguese (Portugal): A t-shirt é branca.

Portuguese frequently adopts modern English words. Although English nouns do not have grammatical gender, they are assigned one when used in Portuguese. T-shirt is feminine, which we can tell by the feminine article A (the) before it and the feminine adjective branca (white) after it.

Why use é instead of está?

The color of a piece of clothing is considered a permanent, core characteristic. For permanent traits, Portuguese uses the verb ser, so we use é (is) here. If you used está (from estar, the temporary 'to be'), it would imply the T-shirt is only white for a little while!

Why does the word for white end in 'a' (branca) instead of 'o' (branco)?

In Portuguese, describing words (adjectives) have to match the gender of the thing they describe. Because t-shirt is a feminine word, the default masculine color branco changes to its feminine form, branca.

How would I change this sentence to say 'This T-shirt is white', using the demonstratives from this lesson?