Abroad 與 go, live, study 等動詞連用時一定用作副詞，此時它意為「在國外；到國外」。例如：
- We intend to go abroad at least once a year from now on. (我們打算從現在起一年至少出國一次) (正)
We intend to go to abroad at least once a year from now on. (誤) - My brother is still living abroad. (我哥哥仍住在國外) (正)
My brother is still living in abroad. (誤) - Blanche would like to study abroad. (布蘭琪想要出國留學) (正)
Blanche would like to study in abroad. (誤) - We’re planning our first trip abroad/overseas. (我們正在規劃我們的首次出國旅遊) (正)
We’re planning our first trip to abroad/overseas. (誤)
一般都認為 abroad 僅當副詞用，若干字典也抱持相同的看法，但若從文法觀點來看，這並不完全正確。事實上，abroad 亦可用作名詞 (意為「國外，海外」)，否則它怎可當介系詞的受詞呢！然而，儘管名詞 (片語) 可當介系詞的受詞，但 abroad 僅能當 from 的受詞，亦即 from 是唯一可以用 abroad 當受詞的介系詞。例如：
- Most of the luxury goods are imported from abroad. (這些奢侈品大多是從國外進口的) (正)
- My parents just returned from abroad. (我父母親剛從國外回來) (正)