Hi Nanako, We use "fall through" to describe a plan or endeavour that has not come to fruition and "fall apart" for several other meanings: (i) disintegration of something that was originally intact or whole. (ii) something that is wearing out due to prolonged use (iii) something that was working but is no longer so (iv) being emotionally overwhelmed or incapacitated. Since your plan for an overseas homestay failed to materialise, I would go with "fall through". However, in my opinion, if you had wanted to dramatise how your travel plans were foiled due to a string of bad luck or unexpected mishaps of epic proportions, you could have used "fall apart" instead. Let's exaggerate: You have planned the perfect homestay, but you missed your flight because you mistook the "12 a.m." departure time for "12 p.m." You rushed to get another ticket over the airline counter at an exorbitant price and the next plane took off, only to make an emergency landing an hour later due to an engine failure. When you finally reached your destination, you were denied entry and turned back as your passport did not meet the minimum expiry requirement. Your plans have really "fallen apart". Your question reminded me of a literature book that my school prescribed when I was a secondary school student. The title of the book is "Things Fall Apart", written by a Nigerian author, Chinua Achebe. In the story, a bright student from Africa had studied overseas and returned home with many ideals; however, his future "fell apart" when he succumbed to pressure from his countrymen and world pleasures and was eventually arrested and brought to court. I hope this helps.

Yes, in everyday conversation, these two phrases would mean the same thing: that your plans didn't work out.

your plans have "fallen through" as it has failed and nothing has come of it. "Fallen apart" would imply something has fallen to pieces or disintegrated

your plans have "fallen through" as it has failed and nothing has come of it. "Fallen apart" would imply something has fallen to pieces or disintegrated

You wouldn't ever really use 'fall apart' to describe plans, unless you really wanted to emphasise that lots of things were going wrong one after the other, which was leading to your plans not being able to happen. If you just want to say in general that your plans can't happen for whatever reason, always use 'fall through'.