TSUMUGU · TBCL 5 (est.) · 語法
是否
grammar point · tier 2 · embedded yes-no: whether (or not)
Folds a yes-no question into a statement as an embedded "whether (or not)" clause; the proposition follows 是否.
Hook inherited from 嗎 .
Folds a yes-no question into a statement as an embedded "whether (or not)" clause; the proposition follows 是否.
框 · Frame
[subj] [verb of asking/knowing/checking] 是否 [proposition]
觸 · Trigger
You want to name an open yes-no question inside a larger sentence, not ask it out loud.
序 · The move
1 Find the host verb of doubt or inquiry: 檢查, 知道, 問, 確認, 想. Is the yes-no part something you report or weigh, not something you fire at a listener?
2 Drop 是否 in front of the whole proposition. Does the clause after 是否 read as a flat statement, no 嗎 and no A-not-A?
3 Leave the sentence as a statement; no rising question particle at the end. If the whole sentence ends without 嗎 or 呢, the embedding is correct.
例 · Examplesshown tap blur
1 每次外出，我一定會檢查to check 是否whether (or not) 帶了have brought 皮包purse / bag 跟鑰匙keys 。
Every time I go out, I always check whether I've brought my purse and keys.
界 · Boundary
嗎 嗎 closes a direct yes-no question you ask aloud and expect answered. 是否 embeds the same yes-no inside a statement, with nothing asked of the listener.
正反問句 (A-not-A) A-not-A (帶不帶) lays both answers out as a spoken question. 是否 carries the same two poles but stays inside a host clause and is written, not asked.
如果…就… 如果 names a condition that triggers a result. 是否 names an open yes-or-no fact under inspection; no consequence is attached.
我想知道你來嗎。 → 我想知道你是否來。
他問我是否來嗎？ → 他問我是否來。
我不確定是不是否下雨。 → 我不確定是否下雨。
English "whether" and "if" both head embedded yes-no clauses, so learners reach for 如果. 如果 is only the conditional "if … then"; the embedded "whether" is 是否.