Meaning: This means that the pig is creating a noise in the pen where it lives.
Choice of Words:Pig is a type of animal. Makes is a verb that means to create or produce something. Sound is a noun that describes something that you can hear. Pen is a small enclosed area where animals are kept. When you put them together, "The pig makes a sound in the pen" means that a pig is producing a sound in the enclosed area where it is kept.
The animal oinks in the enclosure
Meaning: This means that the animal is making a pig-like noise in the space where it lives.
Choice of Words:Animal is a general term for any living creature. Oinks is a verb that describes the sound made by a pig. Enclosure is a noun that describes a space where an animal is kept. When you put them together, "The animal oinks in the enclosure" means that an animal is making the sound associated with pigs in the space where it is kept.