Why Demasiado, not demasiad?

Question

Este contrato, ________cláusulas son demasiado estrictas, no me convence. This contract, whose clauses are too strict, doesn't convince me.cuyas. Hola, why demasiado, not demasiada? I’m confused because cláusula is feminine.  Muchas gracias. Shirley.

Silvia Piriz · Accepted Answer

Hola Shirley S.
Great question! You're absolutely right that "cláusula" is feminine, so using "cuyas cláusulas" is correct — "cuyas" agrees with "cláusulas" (feminine plural), not "contrato".
As for "demasiado", it might seem confusing at first. But in this sentence, it's functioning as an adverb modifying the adjective "estrictas", not as an adjective modifying "cláusulas". Adverbs like demasiado, muy, or bastante don’t change for gender or number, so "demasiado estrictas" is the correct form.
Hope this helps clarify it!
Let me know if you'd like more examples.
Saludos
Silvia