use of prepositions.?

Question

i am from the non english speaking society. nowdays i am trying to speak and write english,but when i started to write english i came accross some confusions about the use of proper prepositions. i came to know that following prepositions are used in following ways-
at- to designate spefic time and spefic address
on- to sedignate days and dates and names of street and avenues
in- use in nonspefic times during a day, a month, a session or a year and use in for the names of land- areas( town, counties, states, countries and continents).
but in the following sentences why we could not use other prepositions instead of used prepositions.
1.After having the several rounds of talks, parties failed to arrive at any consensus. Here why we cannot use on or in instead of at?
2. Seven killed in bus accident. Why cannot use on or at?
3. Security personnel and local people helped in the rescue of the injured passengers.
4.Election will be held on mixed system.

Answer 1

Prepositions are among the most confusing parts of English. You must remember that they vary according to their relationship to the other words of the sentence.
At #1 they used "at" because the direction of the parties talk did not meet. it cannot use "on" at "in" because the sentence focused on the direction, not place of the talk.
#2 "in" is proper. The seven were killed in the bus accident. It shows that they were inside the bus when it had an accident. "on" cannot be used; they weren't on top of it. "at" can be used as well but can show a different meaning. It shows that they would've been near the bus accident and were killed along with it. But the writer wanted to say that they were inside the bus when it happened.
#3 It used "in" because the sentence focuses on both time and place. You can use- they were "at and during" the rescue, using "in" is both of those prepositions at the same.
#4 they used "on" because it shows the manner on how they would use the election.

It gets hard at first to understand the use of prepositions but the key is to read more and get familiar to how certain prepositions are used. You will be able to see that using them uses basic logic, showing that there are big differences with each of its kind.
try this source out to have a better grasp of understanding.

Answer 2

To add to the confusion, different regions use different prepositions to mean the same thing.

For instance, in the USA, we would say "I live ON Main Street", whereas a British speaker would say "I live IN Main Street". We find that funny-sounding here.

Here in Texas, we will wait "IN" line for tickets, but in New York you will wait "ON" line.

There is no way to explain these differences.

The use of prepositions has become idiomatic -- that is, although you could use other prepositions in your sentences above and still have a logical sentence, standard practice dictates which preposition to use -- and they vary from region to region.

The rules of preposition use are generalized -- there are always exceptions, and sometimes they simply don't make sense. As you gain experience with the language (and I certainly don't envy you -- it can be difficult even for native speakers) you will feel more comfortable with these crazy idioms.

By the way, your question was asked in a very understandable manner. Your English usage is quite good and I congratulate you!

Answer 3

1. You 'come to' a consensus. So if you come to something you are AT it. Example. I came to the door so I am AT the door.

2. The people were physically IN the accident. If you think of the accident like a sports field and the people were on the grass, they were contained inside the arena so they were IN it.

3. This one I would use either IN or AT. I think they would both be correct. Example. You could say "I helped at the rescue" because you came to the event (the rescue) so you were AT the event or object. OR "I helped IN the rescue" because you were physically in the rescue.

4. Not so sure about. Sorry