na-adjective
genuine; real; authentic; orthodox
Describes something that is the real thing, not a substitute or imitation; often used for authentic cuisine, traditional methods, or the genuine article.
この店のラーメンは本格的だ。
The ramen at this shop is authentic.
He wants to learn genuine Japanese cooking.
na-adjective
full-scale; full-fledged; all-out; serious
Used when something moves from a preliminary or partial state to a complete, serious, or large-scale implementation; common with nouns like 調査, 実施, 活動, 議論.
来月から本格的な調査が始まる。
A full-scale investigation will begin next month.
夏休みに入って、本格的に勉強するつもりだ。
Now that summer vacation has started, I intend to study seriously.