A到Bgrammar point · tier 1 · A到B — span between two endpoints (from A to B)
· dào
Sets a range between two endpoints: the near end is named, 到 is laid down, then the far end, and the whole stretch between them is taken in.
字源 FORM what the parts do
到 carries 至, an arrow dropped point-down into the ground — arrival; 刀 rides along only for the sound. With one endpoint already named before it, 到 reaches out to a second endpoint after it. The two ends fixed, the run between them is the range.
故事 STORY a scene to remember it by
A finger rests on the first mark, and 到 carries the line out to the second; everything the line crosses belongs to the span.
字源記憶法
框 · Frame
[near endpoint] 到 [far endpoint]
觸 · Trigger
You have a low end and a high end already in mind and want to take in the whole stretch between them.
序 · The move
1Name the near end first — the lower grade, earlier time, smaller number.Is this the end the range starts from?
2Lay 到 down, then name the far end.Does 到 sit between two endpoints of the same kind, not on the back of a verb?
3Read it as 'the near end up through the far end', the whole run included.Does the order run low-to-high, never flipped?
例 · Examples
1三年級third grade (near end)到through to (carries the range to the far end)六年級sixth grade (far end)的同學，下課後都要留下來練習跳舞。
Students from third grade to sixth grade all have to stay after class to practise dancing.
界 · Boundary
從…到…
從…到… marks the start end with 從 as well, bracketing both ends explicitly — 從三年級到六年級. A到B drops 從 and lets the bare near end stand before 到; common when the two ends are a tight, ordered pair (grades, dates, page numbers).
V到 fuses to a verb and marks one far endpoint an action runs up to — 上課上到五點. A到B sits between two named endpoints with no verb on it, taking in the whole stretch between them.
到…去/來+VP
There 到 is the main verb sending the subject to a destination before a purpose verb — 到台北去開會. Here 到 is a connector between two endpoints of a range, acting on neither.
ends flipped: 六年級到三年級 → 三年級到六年級 (the near, lower end comes first)
verb hung on it: 同學練習到 → 三年級到六年級的同學 (到 links two endpoints, it is not tailing a verb here)
endpoint left bare: 三年級到的同學 → 三年級到六年級的同學 (the far end after 到 must be named)
English 'third to sixth grade' can drop 'from'; the slip is carrying that English order into Chinese when the two ends are not already low-to-high, since A到B fixes the near end before 到.