The word "that" is a versatile term in the English language. It can function as a pronoun, a conjunction, or a determiner. For example, when we say, "I like that book," the word "that" helps specify which book we are talking about. It points to something specific, making our communication clearer. In addition to identifying objects, "that" can also connect ideas. For instance, in the sentence, "I believe that climate change is a serious issue," the word "that" introduces a clause that explains what the speaker believes. This use helps to link thoughts and provide more information in a concise way.