… 与否 (האם … או לא)

An attendance decision becomes the topic

• An organiser needs a reply even from people who cannot attend.
• to participate参加cān jiāor not与否yǔ fǒu，all / both都dōuto ask请qǐngsee 尽快尽快jǐn kuàito reply回复huí fù。 — Whether attending or not is the issue; everyone should reply.

Locate the pattern in real examples

• … or not与否yǔ fǒu (whether … or not): success成功chéng gōngor not与否yǔ fǒu,then / just就jiùto see看kànthis这zhèfirst一次yī cì。; to participate参加cān jiāor not与否yǔ fǒu,to ask请qǐngsee 尽快尽快jǐn kuàito reply回复huí fù。
• Read the whole clause before choosing a translation. The examples show the pattern in use; the context below determines what the speaker claims.

Follow the speaker

success成功chéng gōngor not与否yǔ fǒu，depends on取决于qǔ jué yúeffort努力nǔ lì。

• In the opening situation: to participate参加cān jiāor not与否yǔ fǒu，all / both都dōuto ask请qǐngsee 尽快尽快jǐn kuàito reply回复huí fù。
• Whether attending or not is the issue; everyone should reply.

Check the limit of the explanation

• or not与否yǔ fǒu follows the action or property; whether (or not)是否shì fǒu precedes it.
• to participate参加cān jiāor not与否yǔ fǒu and whether (or not)是否shì fǒuto participate参加cān jiā frame the same two possibilities, rather than two successive actions.

Repair the form before interpreting it

• The form or not与否yǔ fǒuto participate参加cān jiā needs repair here. Write to participate参加cān jiāor not与否yǔ fǒu instead; keep the word or frame in its demonstrated order.
• Form and meaning are separate checks. After the repair, explain the sentence in its situation rather than treating a familiar translation as a universal rule.

Keep the distinction

Read the full reference: HSK 6 grammar — Particles.