Love throughout time (an essay I have to do for english class)

The idea of love has changed a lot with the ages. People have always felt this, anyway. But, people started being free to say/show how they really feel and to letting** everyone else know about ther feelings for other people just a couple of centuries ago.
In the middle ages, women and men used to get married because of their parents decision. They hardly ever loved their husbband/wife. In the 19th century people started falling in love a little bit more freely. Even in literature, one of the main topics was love, like in the novel "Pride and Prejudice" by Jane Austen.
In the 20th century things evolved a lot more and families didn't have as much opinions in influence on marriage. By the 21th century, the idea of love changed completely. Before, couples proved their love with marriage. Now, that is no so important. At least not for everyone. Now, there even exists something call common law marriage, couples don't get married in a church or even sign a paper. They just say they are married and live together and that's it.
In my opinion, things have changed a lot throughout time.

Well written María! La oración "people started being free to say/show how they really feel and letting everyone else know about ther feelings for other people" es un poco deficil por que hay dos maneras en que se puede leerla. 

People started being free to say how they feel y tambien being free to let everyone else know.

o

People started being free to say how they feel y tambien started letting everyone know.

Para clarificar cual qieres decir, puedes escribir o "People started being free to say how they feel and to let everyone else know" o "People started being free to say how they feel and started letting everyone else know".