When describing a person's facial expression or sign of happiness, there are several synonyms that can be used instead of "he smiled to see her so happy." Some alternative words which convey the same emotion include grinned, beamed, smirked, twinkled, chuckled, and glowed. These synonyms provide a variety of descriptive words to paint a picture of the person's joy and happiness, while providing more color and depth to the sentence. Using alternative words spices up your writing and makes your work more interesting to read.