"He is thin" or "he is slender" are both common ways to describe someone who is thin in English. Other words that could be used to describe someone who is thin include "skinny," "slim," or "lean." It's important to be mindful of the language you use to describe someone's physical appearance, as it's possible that using certain words could be perceived as being rude or offensive. It's always best to be respectful and considerate when describing someone's appearance.
