adverb
Describes doing something with another person or thing, or things happening at the same time. Often used adverbially.
家族と共に過ごす時間が一番大切だ。
Time spent together with family is the most important.
彼らは共にプロジェクトを完成させた。
They completed the project together.
adverb
at the same time; along with; as
Common in the pattern ...と共に, meaning 'together with', 'as', or 'at the same time as'. Can also mean 'including' or 'along with' when listing items.
年を取ると共に、体力が落ちてきた。
As I get older, my physical strength has declined.
彼は友人と共に旅行に出かけた。
He went on a trip along with his friend.
adverb
Used to refer to two things or people together, often in the pattern AもBも共に. Emphasizes that both share a quality or action.
兄も姉も共に医者です。
Both my older brother and older sister are doctors.
二つの案は共に一長一短がある。
Both proposals have their merits and demerits.