Describe how a covalent bond can involve a sharing of the electrons but still develop charges on the atoms.?

If the electrons in a covalent bond are not shared equally, then one atom gets a partial positive charge, and one (the one where the electrons spend most time) gets a partial negative charge. This is a result of differences between the two atoms in their electronegativity values. This then results in what is referred to as a polar covalent bond.