Wash hands with warm, soapy water for 20 seconds.
If using fresh green beans, wash and cut into 1-inch pieces. If using canned, drain and rinse green beans under cool water.
Heat oil in skillet or electric skillet over medium heat.
Add onion and celery. Cook slightly.
Add green beans, water, and sugar to skillet.
Cover and cook on low about 25 minutes or until beans are tender. Frozen and canned green beans will cook faster.