Here's why:

* Electronegativity: Nonmetals generally have high electronegativity, meaning they have a strong attraction for electrons. They are less likely to lose electrons and more likely to share them to achieve a stable electron configuration.

* Sharing Electrons: Covalent bonding involves the sharing of electrons between atoms to form a stable molecule. Nonmetals are well-suited to this type of bonding because they can achieve a full outer shell of electrons by sharing.

Common examples of elements that form covalent bonds include:

* Group 14 (Carbon Group): Carbon (C), Silicon (Si), Germanium (Ge)

* Group 15 (Nitrogen Group): Nitrogen (N), Phosphorus (P), Arsenic (As)

* Group 16 (Oxygen Group): Oxygen (O), Sulfur (S), Selenium (Se)

* Group 17 (Halogens): Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I)

Important Note:

While nonmetals predominantly form covalent bonds, there are some exceptions. For example, hydrogen (H) is a nonmetal, but it can also form ionic bonds with very electronegative elements like oxygen (O) to form water (H₂O).

Let me know if you'd like more details on specific covalent bond types or examples!