以及grammar point · tier 1 · 以及 — and (joins the last item, often the fuller one, onto a list)
And: caps a list by reaching out to one more item, often the longest or the one that matters most, in formal or written register.
字源 FORM what the parts do
以 is grammar's quiet connector, the with/by tool that mounts the next word. 及 is a hand (又) closing on the person ahead (人): to reach, to catch up. Joined, they reach forward to the last item and pull it into the list.
故事 STORY a scene to remember it by
Items are lined up in a row, and a hand reaches past them to the one trailing at the end and draws it in with the rest.
字源自撰記憶法
框 · Frame
[item A]、[item B]，以及 [final item]
觸 · Trigger
A list is running; cap it by reaching out to the last item, often the longest or weightiest one.
序 · The move
1Line the earlier items up with 、(or 和) between them.Are they all noun-like phrases sitting in one series?
2Place 以及 right before the final item.Is this the last item, the one that closes the list? 以及 caps; it does not sit between every pair.
3Let the final item be as long as it needs, then close the list.Does the register read formal or written? In casual speech 和 alone usually does the job.
例 · Examples
1我把(disposal marker)旅行中during the trip遇到to meet, run into的人the people、有趣的事interesting things，以及and (also)看到saw的美景the beautiful scenery說給大家聽told everyone (lit. said for all to hear)。
I told everyone about the people I met on the trip, the interesting things that happened, and the beautiful scenery I saw.
和 stands two items side by side as an equal swappable pair (大人和小孩); 以及 reaches forward to cap a list with its last, often heavier, item and reads more formal. Pairing two versus closing a series.
以及 joins noun-like items in one list; 而且 stacks a second whole clause onto the first. Listing things versus adding a statement.
✗ 我喜歡茶以及咖啡。 → ✓ 我喜歡茶和咖啡。 (a plain two-item pair in speech wants 和; 以及 over-formalizes it.)
✗ 蘋果以及香蕉以及橘子 → ✓ 蘋果、香蕉，以及橘子 (use 、between earlier items; 以及 caps only the last one.)
✗ 他很高以及他很瘦。 → ✓ 他很高，而且很瘦。 (joining two clauses wants 而且; 以及 links list items.)
English 'and' caps a list the same way no matter how formal ('apples, bananas, and oranges'). 以及 is the written/formal cap; for everyday two-item lists Mandarin reaches for 和, not 以及.