と共に【とともに】

The expression と共に is used to express "together with", "at the same time as", or "as well as". It has three main usages depending on context:

1. Together with (companionship / involvement)

When attached to a noun, と共に can mean "together with" someone or something, indicating that an action is done jointly or in collaboration.

This usage is more literary and formal than simply using といっしょに一緒に. It is commonly found in written language, speeches, and formal contexts.

2. At the same time as (simultaneous change)

と共に can express that two things happen simultaneously, or that one thing changes in tandem with another. This is used to describe gradual or correlated changes.

When used with verbs, the dictionary form precedes と共に:

3. As well as (addition)

と共に can also mean "as well as" or "in addition to", listing multiple qualities or roles that something or someone has.

This usage emphasizes that both things are true at the same time.

Notes

• と共に is significantly more formal than といっしょに一緒に or とともに written in hiragana. It appears frequently in news articles, essays, and formal speech.
• When expressing simultaneous change (usage 2), it is similar to につれて and にしたがって, but と共に emphasizes that the two events occur at the same moment rather than one causing the other.