[noun] + だけでなく(て) + ~も
[verb (plain)] + だけでなく(て) + ~も
[i-adj] + だけでなく(て) + ~も
[na-adj (な)] + だけでなく(て) + ~も
Note: て is optional; both だけでなく and だけでなくて are used.
The structure だけでなく(て)~も is used to express "not only… but also…". It indicates that something applies beyond just the first item mentioned, extending to an additional item or scope. This pattern can follow nouns, verbs, and adjectives.
The pattern highlights that something is true not just for one thing, but also for another.
When used with verbs, the plain form precedes だけでなく.
Both forms are interchangeable. The version with て (だけでなくて) sounds slightly more conversational, while だけでなく without て is common in both spoken and written Japanese.