Here's why:

* Electron configuration: Sulfur has 6 valence electrons (electrons in its outermost shell). It needs 2 more electrons to achieve a stable octet configuration.

* Covalent bonding: Sulfur achieves this stability by sharing electrons with other atoms through covalent bonds.

* Two bonds: To gain 2 electrons, sulfur forms two covalent bonds.

Let me know if you have any other chemistry questions!