are both这里both是副词，We are both teachers.both are这里both是代词，作主语。Both are teachers.
both双语例句
1.Both bodies had been mutilated.
两具尸体均残缺不全。
2.both exhibited megalomaniac tendencies
两者都表现出了夸大狂的倾向
3.Both organisms are infectious.
两种生物都会传染疾病。
4.Both parents are working.
父母双方都在工作。
5.Microfibre fabrics are both water-resistant and windproof.
微纤维面料既防水、又防风。