Carbon Forms Covalent BondsThe most common type of bond formed by carbon is a covalent bond. In most cases, carbon shares electrons with other atoms. This is because carbon typically bonds with elements which have a similar electronegativity. Examples of covalent bonds formed by carbon include carbon-carbon bonds and carbon-hydrogen bonds.
Carbon forms polar covalent bonds with elements that have a slightly different electronegativity. The carbon-oxygen bond is a polar covalent bond. It is still a covalent bond, but the electrons aren't shared equally between the atoms. If you are given a test question asking which type of bond carbon forms, the answer is a covalent bond.
Less Common Bonds with CarbonHowever, there are less common cases in which carbon forms other types of chemical bonds. For example, the bond between calcium and carbon in calcium carbide, CaC2, is an ionic bond. Calcium and carbon have different electronegativities from each other.
More About BondsDifference Between Ionic and Covalent Bonds
Types of Chemical Bonds
Chemistry Cat - Covalent Bond