This is the present perfect tense: Eg. I have lived in France for 1 year - meaning that I am still living there now. Past perfect tense: I had lived in France for 1 year - meaning that something happened which means I don’t live there now. In your example, the reason for present perfect tense (I have/ they have) is because the people are still abroad now; and the houses are still standing now. You can also use simple tense (they were abroad) but this implies that they aren’t abroad anymore. Same for the houses: if you said ‘the houses were standing…’ it implies that the houses aren’t there anymore. He watched lots of videos can work in simple past tense, as he watched the videos in the past and has finished the action of watching now.

1. "Over several days" - Preposition: Over - Why: Describes actions happening intermittently within a time frame. - Example: He watched videos at different times across several days. Tip: Use "over" for scattered actions across a period. 2. "For 5 days" - Preposition: For - Why: Refers to the full duration of time. - Example: They were abroad continuously for five days. Tip: Use "for" to show how long something lasted. 3. "In the last 8 years" - Preposition: In - Why: Refers to actions or events that occurred at some point during a completed period of time leading up to now. - Example: Many homes have been built in the last 8 years. Tip: Use "in" to highlight occurrences within a specific time frame that is viewed as a whole. General Tip: Match prepositions with the time relationship: - Over: Scattered actions. - For: Continuous durations. - In: Within a time span.

Each preposition has an underlying basic meaning: "over" means above or looking down upon "for" denotes connection or attachment of one thing to another "in" conveys containment of one thing inside another All other uses of the prepositions are metaphorical, but always based on the underlying basic meaning. In your examples, the prepositions are interchangeable. The meaning does not change if you replace one with another. However, each preposition creates a different mental image: "over several days" creates an image of looking down upon those days, or seeing them as a whole from the perspective of an observer "for several days" creates an image of linkage or attachment to those days. "in several days" creates an image of containment within that time period.

More prepositions Over: during For: for that time period

And about prepositions: we use different prepositions of time and place. Usually ‘in, at, on’. Each one is used in different context, and those are the grammar rules ☺️ Generally the rules are: In: inside (a place, a longer time period) At: a location or time On: on top of, on a day or date. You can find out the rules from many resources online, or most teachers (myself included) would recommend the Murphy Grammar book for specific grammar study. This is one of the best resources for grammar learning and can help you master these prepositions, unless you are taking English classes with a professional teacher 😉 Hope this helps! Teacher Pip