1. We'll leave after lunch.
2. We'll leave in lunch.
(Can we use both preposition? Are both OK? What is the difference between them?)
3. He was dead in a few seconds.
4. He was dead after a few seconds.
(is there any difference between them? Can we use both prepositions?)
5. They will leave for London after 10 minutes.
6. They will leave for London in 10 minutes.
(Does #5 mean that they will leave for London after 10, 15, 20 minutes....? Any time after 10 minutes? Does #6 mean they will leave for London shortly after 10 minutes? What is the difference between them?)
1 & 2: 1 is find, using "after". That means after we have eaten our lunch, or after the lunch period. #2 is not correct. "In" lunch? There's a fly in my soup? What is in lunch? Too much garlic? You could say you will leave during the lunch period. It does NOT mean after lunch. It really means nothing.
3 & 4: Both mean the same thing in this instance. In both, using in and after, it means he died after the elapse of a few seconds.
5 & 6: leaving after 10 minutes could mean any time after ten minutes has elapsed. It really doesn't make much sens. #6 is correct. We will leave in ten minutes (when the train is scheduled to leave, or when the timer goes off, or for whatever reason you must wait ten minutes to leave).
1. "We'll leave after lunch." This sentence indicates that the departure will take place once the meal is finished. Here, "after" is used as a time-related preposition to indicate the point in time when the action will occur.
2. "We'll leave in lunch." This sentence is not idiomatic and may not accurately convey your intended meaning. It would be better to use "during" or "within" instead of "in" to express the duration or time period of the departure.
Regarding the difference between the two prepositions "after" and "in" in this context, "after" emphasizes a delay or a time gap between the lunch and the departure, whereas "in" suggests that the departure is happening concurrently with the meal.
3. "He was dead in a few seconds." This sentence implies that the individual died within a short period of time, almost instantaneously. Here, "in" is used to denote a duration or a short time span.
4. "He was dead after a few seconds." This sentence suggests that the person died sometime after a few seconds had passed. "After" signifies a time interval between the event (in this case, death) and the reference point (the few seconds).
The difference between #3 and #4 is that #3 implies immediate death, while #4 suggests a slight delay before the person's demise.
5. "They will leave for London after 10 minutes." This sentence means that the departure will take place once exactly 10 minutes have passed. It implies a specific and fixed duration of 10 minutes.
6. "They will leave for London in 10 minutes." This sentence indicates that the departure is scheduled to happen 10 minutes from now. It implies that the departure is imminent and will happen shortly after the 10-minute period.
The key difference between #5 and #6 is that #5 specifies a precise time point (after exactly 10 minutes), while #6 denotes a timeframe in the future (10 minutes from now).