There refers to place. Their refers to possession. Its shows possession. This is a demonstrative pronoun which must be used with another word. Singular subjects require singular verbs.
Plural subjects require plural verbs.
Bob and Sue watch television. Be careful when identifying the subject of the verb. Four rules to remember when using commas. Use a comma to separate words in a series. Use a comma between independent clauses joined by and, so, or, nor, but, for, yet.