4. Son las plumas de ella
The answer could be "no escribo" I do not write...
This would be something equivalent to the Town Square or The Main market, and in Spanish this would be called "Plaza".
So for example, this place in Mexico City is called Plaza de la Constitución (although it's known as Zocalo to most)
It should be hablé since if it talking about someone else. If it were to be you, however, the sentence would be “Yo hablo con Juan.” Comprende?
Que es una infinita? Que no tiene ni puede tener fin ni límites o que es muy numeroso o muy grande