What it means
ともなると marks a significant stage, circumstance, or point in time and presents the consequence that naturally arises once that condition is reached. It often carries the nuance of “when it comes to” or “once it becomes,” rather than merely indicating a neutral time relationship. The construction is common in formal writing, commentary, and serious statements about predictable changes in behavior, demands, or circumstances.
Usage note
ともなると usually implies that the condition brings about a notable or expected consequence; it is not simply interchangeable with a neutral temporal expression such as とき. It commonly follows a noun or a verb in the dictionary form, and the surrounding sentence may still use either familiar or polite endings.
How to use it
年度末ともなると、業務が集中します。
When it is the end of the fiscal year, work becomes concentrated.
海外で暮らすともなると、生活費の計画が必要になります。
Once it comes to living abroad, planning living expenses becomes necessary.
年度末ともなると、業務が集中する。
When it is the end of the fiscal year, work becomes concentrated.
海外で暮らすともなると、生活費の計画が必要になる。
Once it comes to living abroad, planning living expenses becomes necessary.
Example sentences
責任者ともなると、休日でも急な連絡に対応しなければならない。
Once someone becomes responsible for an organization, they must respond to urgent messages even on holidays.
海外で暮らすともなると、言葉だけでなく生活習慣にも適応する必要がある。
Once one comes to live abroad, it becomes necessary to adapt not only to the language but also to the local customs.
初めて子どもを育