Comma splice: My family eats turkey at Thanksgiving, we eat ham at Christmas.
Correct: My family eats turkey at Thanksgiving, and we eat ham at Christmas.
Correct: My family eats turkey at Thanksgiving. We eat ham at Christmas.
Correct: My family eats turkey at Thanksgiving; we eat ham at Christmas.
Fused sentence: I bought a chocolate pie from the bakery it was delicious.
Correct: I bought a chocolate pie from the bakery. It was delicious.
Correct: I bought a chocolate pie from the bakery, and it was delicious.
Correct: I bought a chocolate pie from the bakery; it was delicious.