Having a dog as a companion is well worth the trouble and expense.
When analyzing a text, one of the things we must look for is whether an opinion, or purely factual information, is being used. In order to do this, we need to figure if the information in the text, or sentence, is verifiable, using proof, and if it states fact, or, if, on the contrary, it shows the position or views, of a writer. The best way to do this, as said before, is to read the sentence carefully and check if the data given in the sentence comes from easily verifiable academic data, or if it shows, through more informal vocabulary, a position on a point, which depends entirely on the view of the writer and cannot be easily verified through formal facts. In this particular case, the one sentence that shows this opinion, which does not come from fact, but rather from a personal experience, is: Having a dog is well worth the trouble and expense because this clause depends exclusively on the experienced lived through by the writer, or speaker.
