Corrected sentence:
Elephants use their trunks to smell, hold things, and even as snorkels when they swim.
Why this is correct (easy steps):
- "Elephants" is plural, so we use "use" (not "uses").
- Each elephant has a trunk, so we say "their trunks" to match the plural subject.
- The list of actions should match in form: smell, hold things, and even act as snorkels when they swim.
Another way to say it for one elephant:
An elephant uses its trunk to smell, hold things, and even as a snorkel when it swims.
Short examples: They can sniff flowers, pick up food, and breathe through their trunk while swimming.