When the same verb would repeat in a balanced second half, leave it out. The reader fills it in from the first half: "Mei ordered coffee, and Lars ordered tea" tightens to "Mei ordered coffee, and Lars tea." The full version isn't wrong — just heavier. What this cut needs is not a formal setting but a strictly parallel pair of halves: the second has to line up with the first piece for piece, or the reader cannot rebuild the missing verb. Given that parallelism it is at home anywhere, in speech as much as in writing — "Mei ordered coffee, and Lars tea" is ordinary spoken English.
Drop the repeated verb in the second half
Mei ordered coffee, and Lars ordered tea. → Mei ordered coffee, and Lars tea.
Sofia teaches Monday, and Hiroshi teaches Wednesday. → Sofia teaches Monday, and Hiroshi Wednesday.
Wei handles marketing, and Diego handles logistics. → Wei handles marketing, and Diego logistics.
Not "Mei handles marketing, and Lars handles finance." — say "Mei handles marketing, and Lars finance.". The second handles just repeats the first, so leave it out: and Lars finance.
Try it: Amina chose the blue design, and Mateo chose the green one. Tighten the second half: drop the repeated verb. (Leave out the word you don't need.) Answer: Amina chose the blue design, and Mateo the green one. — The second chose just repeats the first, so the tighter version drops it: and Mateo the green one. "Chose" is the repeated verb the reader can fill in, so it is left out. Gapping keeps balanced halves lean.
With a helping word, drop both it and the verb
When the repeated part includes a helping word like will or should, leave out both the helping word and the verb in the second half: "Mei will lead marketing, and Lars will lead finance" tightens to "Mei will lead marketing, and Lars finance." In this pattern cut them as a pair: "and Lars will finance" does not work, because finance then reads as the verb rather than the thing. Keeping the helper is its own separate pattern with the verb gone instead — "Mei will lead marketing, and Lars will too" — which is also good English, just a different cut. Like plain gapping, this one wants parallel halves that balance cleanly.
Mei will lead marketing, and Lars will lead finance. → Mei will lead marketing, and Lars finance.
Diego should review section one, and Camila should review section two. → Diego should review section one, and Camila section two.
Sofia will chair the morning session, and Hiroshi will chair the afternoon. → Sofia will chair the morning session, and Hiroshi the afternoon.
Not "Mei will lead marketing, and Lars will lead finance." — say "Mei will lead marketing, and Lars finance.". Both will and the verb repeat, so leave them out: and Lars finance.
Try it: Lani will present first, and Farid will present second. Tighten the second half: drop the repeated helping word and verb. (Leave out the words you don't need.) Answer: Lani will present first, and Farid second. — The second half repeats will present, so both the helping word and the verb drop out: and Farid second. "Will present" is the repeated part the reader fills in, so it is left out. With a helping word, you cut the pair together.
Let a wh-word stand for the whole clause
A wh-word — who, what, where, when, why, how — can stand in for a whole clause that would only repeat what was just said. After verbs like know, ask, wonder, remember, say, tell, drop the echoed clause and let the wh-word carry it: "Someone called, but I don't know who called" tightens to "...I don't know who." This is the boldest of these cuts — gapping drops the verb, but here the wh-word swallows the whole clause. Unlike gapping, it reads natural in ordinary speech as well as writing, so reach for it any time the full wh-clause would just echo the sentence.
Someone called, but I don't know who called. → Someone called, but I don't know who.
They changed the plan, but nobody said why they changed it. → They changed the plan, but nobody said why.
She's leaving, but she wouldn't tell me when she's leaving. → She's leaving, but she wouldn't tell me when.
Not "Someone called, but I don't know who called." — say "Someone called, but I don't know who.". who already stands for the whole clause, so adding called just repeats it — leave it out.
Try it: Someone called, but I don't know who called. Replace the repeated clause with just the wh-word. (Leave out the words you don't need.) Answer: someone called, but I don't know who. — The wh-word alone stands in for the whole repeated clause: but I don't know who. "Who called" repeats what was just said, so it is left out and who carries it. This trick keeps the sentence short and natural.