How do you make the Spanish word tengo feminine?

You can't make the Spanish word "tengo" feminine.

Here's why:

* "Tengo" is the first-person singular form of the verb "tener" (to have). Verbs don't have gender in Spanish.

* Gender in Spanish primarily applies to nouns and adjectives.

To express possession in the feminine form, you would change the noun to be feminine, not the verb.

For example:

* Masculine: Tengo un libro. (I have a book.)

* Feminine: Tengo una pluma. (I have a pen.)

In both cases, the verb "tengo" remains the same. The gender is indicated by the noun ("libro" vs. "pluma").