Here's why:

* Covalent bonds involve the sharing of electrons between atoms. In a water molecule, the oxygen atom shares electrons with each of the two hydrogen atoms.

* Ionic bonds involve the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions that attract each other.

While oxygen is more electronegative than hydrogen, meaning it attracts electrons more strongly, it doesn't completely remove electrons from the hydrogen atoms. Instead, the electrons are shared in a polar covalent bond. This creates a slightly negative charge on the oxygen atom and slightly positive charges on the hydrogen atoms.