How to say "inflatable" in Japanese

• 膨張式ぼうちょうしき
  nounLess common. Covers 'needs to be inflated for normal use' — literally an 'expansion type' — describing things pumped up before use, such as a boat or air mattress.
• 可膨張式かぼうちょうしき
  nounLess common. Covers 'can be inflated', stressing capability rather than necessity: it suits contexts where the point is simply that something can be inflated, not that it must be inflated for normal use.
• インフレータブル
  no-adjectiveLess common. A katakana loanword covering 'inflatable' in general, without the finer distinction between 'must be inflated' and 'can be inflated'; typical contexts include product names and descriptions.

All three are less common renderings of 'inflatable': pick 膨張式 for things that must be inflated for normal use, 可膨張式 for things that merely can be inflated, and the loanword 「インフレータブル」 for the general sense.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 膨張式ぼうちょうしきinflatable (in the sense of "needs to be inflated for normal use")
• 可膨張式かぼうちょうしきinflatable (in the sense of "can be inflated")
• インフレータブルinflatable