Note: A version of (11) but with a plural subject is perfectly acceptable:

But despite the grammatical similarity, this is quite a different type of sentence from (11). The sentence above does not indicate that a certain event occurred several times. Rather, it makes the general statement that all houses (within a certain context) tended to change hands several times. In other words, the phrases varias veces and cambiaban de manos form a single dispositional term. The dispositional sense of cambiar de manos varias veces is disallowed when the verb takes a singular subject, however. (Back to main text)