Practicas tú estas palabras.

This sentence is from lesson 11.6. Can someone explain the purpose and placement of "tú" in the sentence? "Practicas estas palabras" would convey the same meaning. If the purpose was to emphasize who should be performing the action, why was it not placed ahead of the verb as is sometimes done, as in "Yo limpié la casa. Tu vi la televisión."

I think the "tú" is for emphasis and that this is also some form of the imperative. If think if you lead off with "tú", it sounds like a normal declarative sentence.