Question

Change the adjective below to a superlative by adding the appropriate ending (ísimo). altas

Answer 1

A superlative is the highest quality or degree of a word. In your question that wants to give the superlative of the word "Altas" would be "Altisimas". I hope you are satisfied with my answer and feel free to ask for more question or clarifications. Have a nice day 

Answer 2

The correct answer is altísimas.

The word altas (which means tall) is used in the feminine form, plural. It is the plural feminine form of alto. In order to form the superlative, we just need to add -ísimo. But since it is feminine, we should add -ísima. But since it is plural, we also need to add -s to make -ísimas.