这个计划成功英文可以用 "The plan was successful" 来表示。

"Successful" 是形容词,意思是 "achieving the desired result; effective"。

例如:

The plan was successful in increasing sales. (计划成功地提高了销售额。)
The team's efforts were successful in finding a solution to the problem. (团队的努力成功地找到了解决问题的方案。)

"Successful" 来自英文 "success",意思是 "the achievement of something desired, planned, or attempted"。

例如:

The company's success is due to its innovative products and excellent customer service. (公司的成功归功于其创新产品和优秀的客户服务。)
She was determined to succeed in her career. (她决心在职业生涯中取得成功。)