Adverbs of Degree: Invariable
When describing the intensity of something, you can use bastante (quite / rather / enough) and demasiado (too / excessively).
When these words modify an adjective, a verb, or another adverb, they act as adverbs. This means they are invariable and never change form, regardless of the gender or number of the things you are describing.
| The suitcase is quite full and the coat does not fit. | A mala está bastante cheia e o casaco não cabe. |
| The zipper is going to burst because the suitcase is too heavy! | O fecho vai rebentar porque a mala está demasiado pesada! |
| We are too close to the limit. | Nós estamos demasiado perto do limite. |
Quantifiers: Variable
When bastante and demasiado modify a noun, they act as quantifiers (meaning "quite a lot of / quite a few" and "too much / too many"). In this role, they must agree with the noun they describe.
Demasiado agrees in both gender and number with the noun, taking the forms demasiado, demasiada, demasiados, and demasiadas.
| You have too many things in the suitcase and the shoes do not fit. | Tens demasiadas coisas na mala e os sapatos não cabem. |
| It is possible that you are taking too much unnecessary clothing. | É possível que leves demasiada roupa desnecessária. |
Bastante is gender-neutral, so it is used for both masculine and feminine nouns. However, it still agrees in number, adding an s to become bastantes when describing plural nouns.
| You are taking quite a few unnecessary sweaters for the trip. | Levas bastantes camisolas desnecessárias para a viagem. |
