Here's why:
* Open Syllable: An open syllable ends with a vowel sound.
* Closed Syllable: A closed syllable ends with a consonant sound.
In "babies", the first syllable "ba" ends with a vowel sound (the "a" sound), making it an open syllable. The second syllable "bies" ends with a consonant sound (the "s" sound), making it a closed syllable.