Which of the following is an example of informal language?

The phrase "Hey there" is an example of informal language because it is a casual greeting commonly used in everyday conversations among friends, family, or acquaintances. Informal language tends to be more relaxed and less structured than formal language, making it more approachable and friendly. This type of expression often reflects a conversational tone and is typically used in non-professional settings.

In contrast, the other phrases— "subsequently," "further," and "to conclude"—are examples of formal language. "Subsequently" is an academic or professional term that signifies a sequence of events. "Further" can also be seen as more formal, often used in writing to expand on points or ideas. "To conclude" is typically employed in formal essays, speeches, or presentations to indicate that the speaker is summarizing their points or finishing their discussion. Thus, these expressions do not carry the same casual tone found in "Hey there."