英语单词legal，lawful和legitimate都有“合法的”这种意思，但是它们的内涵并不完全一样，不能等同。

Legal主要是指concerned with or relating to the law(与法律有关的)；if some⁃thing is legal, you are allowed to do it or have to do it by law(如果某件事是合法的，法律就允许你做或你必须做)，比如，legal ad⁃vice和legal system。

Lawful意为allowed or recognized by law(法律允许的或法律承认的)，比如，lawful marriage和lawful method。

Legitimate是指fair or reasonable(公平的或者合理的)；acceptable or allowed by law(被法律接受的或者法律允许的)比如，legitimate business，legitimate government和legitimate sons。

实例：公司职工依法组织工会，开展工会活动，维护职工的合法权益。

译文：The employees of a company shall organize a trade union in accordance with the law, carry out trade union activities and protect their lawful rights and interests.

依据以上的分析，本句译文中的lawful应改为legitimate，才会显得更为准确、严谨。