stranger、foreigner、alien与immigrant这些名词均有“陌生人、外人”之意。
stranger : 指对当地的生活习惯、语言等不熟悉，或为某团体不熟的人，也指不认识的人。
- My mother always warned me not to talk to strangers.
我母亲总是告诫我不要和陌生人讲话。 - I'd never met anyone at the party before - they were complete strangers.
聚会上的人我以前从未见过——全是陌生人。
foreigner : 指在异国作短期访问或长期居住的外国人。
- The fact that I was a foreigner was a big disadvantage.
我是外国人这事实对我十分不利。
alien : 指没有成为侨居国正式公民的移民。
- When war broke out the government rounded up thousands of aliens and put them in temporary camps.
战争爆发时，政府把数以千计的外国人集中在一起，关在临时拘留营中。
immigrant : 指在别国定居并取得所在国国籍的外国人。
- Immigrants have contributed to British culture in many ways.
移民在许多方面都对英国文化有所贡献。 - Illegal immigrants are sent back across the border if they are caught.
非法移民如果被抓住就会从边境被遣返。
