correct form of tener dos casas
The correct form of the verb "tener" (to have) to express the idea of "having two houses" is:
"Tenemos dos casas."
To form this sentence correctly, you need to conjugate the verb "tener" to agree with the subject of the sentence. In this case, the subject is "we" (nosotros). The conjugation of "tener" for "we" in the present tense is "tenemos."
So, to express the idea of "having two houses" in Spanish, you say "Tenemos dos casas."