General opposites:
* Grande: This is the most common and direct opposite, meaning "big" or "large."
* Largo: This is used when referring to length or width, meaning "long."
* Ancho: This is used when referring to width, meaning "wide."
* Alto: This is used when referring to height, meaning "tall."
* Mayor: This is a more formal opposite, meaning "greater" or "larger."
Specific opposites:
* Grande: If "pequeno" refers to size, then "grande" is the opposite.
* Largo: If "pequeno" refers to length, then "largo" is the opposite.
* Ancho: If "pequeno" refers to width, then "ancho" is the opposite.
* Alto: If "pequeno" refers to height, then "alto" is the opposite.
* Mucha: If "pequeno" refers to quantity, then "mucha" (much) is the opposite.
It's important to consider the context in which "pequeno" is used to determine the most accurate opposite. For example, if someone says "un coche pequeño" (a small car), the opposite would be "un coche grande" (a big car).
Let me know if you have a specific sentence or situation in mind and I can help you find the most appropriate opposite!