"和他在一起" 的英语表达为 "to be with him" 或 "to be in his company"。
来源：
"to be with" 是一个常用的短语，表示 "和...在一起"。
"to be in someone's company" 也是一个常用的短语，表示 "和某人在一起"。
英文例句及中文翻译：
I enjoy to be with him. (我喜欢和他在一起。)
I feel happy to be in his company. (我感到高兴和他在一起。)
She pkes to spend time with him. (她喜欢和他在一起。)
I love to be around him. (我喜欢和他在一起。)