Are there any alternative of "Do you charge for a plastic bag?"

 You're looking for different ways to ask about plastic bag charges. Here are some alternatives, ranging from direct to more polite/indirect:

Direct & Common:

• "Do you charge for bags?"

• "Is there a charge for a plastic bag?"

• "Are plastic bags extra?"

• "How much is a plastic bag?"

More Polite/Indirect:

• "Will there be a charge for a bag, please?"

• "Do you provide complimentary bags, or is there a cost?"

• "Is it okay if I don't take a bag, or will I be charged if I do?" (This is if you want to avoid a charge)

• "Just confirming, are bags charged here?"

Assuming a charge and asking about it:

• "What's the fee for a bag?"

• "Could you tell me the cost of a plastic bag?"

In a practical scenario, especially in Japan where charges are common:

Often, the cashier will ask YOU if you need a bag (e.g., "レジ袋ご利用ですか？" - Reji-bukuro go riyō desu ka? - "Would you like a shopping bag?"). If you want one, you can say "はい、お願いします" (Hai, onegai shimasu - "Yes, please"). If you don't, you can say "いいえ、けっこうです" (Iie, kekkō desu - "No, thank you").

If they don't ask and you need one, you might say:

• "袋、お願いします。" (Fukuro, onegai shimasu - "A bag, please.") - This implies you'll pay if there's a charge.

The best alternative depends on the specific context and how you want to frame the question.