Translation:The class ended at 3 P.M., and I went home.
You have already known them. I don't force you use these. But maybe there are any people who don't know about them yet. I am writing for some people who have interested in Japanese language. We can write one sentence without these. But I think that using these are needed when we write multiple sentences. To use 句読点（くとうてん）is easy than to use comma and period when input Japanese sentences. Because you use Japanese input mode at the time. But you are free. Don't mind my comment. :)
Having a te form verb in the middle of the sentence like that is traditionally translated by that action followed by an "and", but I noticed in another sentence in the course that duolingo allowed the "after ~" translation, which is where I think the confusion comes in. "After" can convey the same meaning, but if you want to be accurate to what is being said in Japanese, it's better to use a "~ and ~" translation.
"And" is virtually never wrong but these verbs can form long strings and it does not make good English translation to use "and... and... and... " to link clause after clause. The general rules for "....te, .....te, ...te, ....final verb" structures are: 1. The clauses are in order of occurrence. 2. They are also in order of ascending importance, the final verb being the most important and determining the tense/aspect of the sentence. 3. If the verbs are logically coordinate, "and.... and ...and" is correct if the translation keeps the clauses in the order of occurrence. 4. Logical subordination (after, by, because, etc.) always subordinates earlier verbs in the series to verbs later in the series and makes the final vêrb the head of the structure.
- The "te" form is conjunctive.
- It links with some following verb and is in order of occurrence with that verb .
- In a series of "te" forms with a series ending form, the verbs in the series are in order of occurrence.
- Consequently, it is possible to translate the "te" form by "and" and be techinically correct in almost every case.
- However, the unexpressed logical connection between the verbs in the series can be simple paring, cause and effect, or just about anything except contrast. So, translating "te" by "and" can be basically correct but squeeze the life out of the translation.
The "-te" form is a conjunctive form that attaches to verbs. In general, it means that there is a logical connection between the verb it attaches to and the verb to which it relates (last verb in the series). The logical connection can be simply conjunctive or more complicated (sequence, manner, means, etc.) but the verbs are always in order of occurrence. The logical connection is implied by context and must be supplied in translation. ("But, although, however", and any other adversative or contrastive interpretations are not indicated by the "te" form without "mo" or another clear indicator. ")
おわって is from the intransitive verb 終わる, thus it doesn't have a direct object. "the class was finished" means it was finished by someone, someone has finished it. and that is wrong. instead, it just finished, or has finished.
on the side note, the transitive verb to finish (something) in Japanese is 終える.
Is this duolingo being picky or am I misunderstanding the difference between the structures:
The first is "The class ended at 3pm and I went home" and when I tried to put "Work ended and I went home" for the second, I was marked wrong.
The second wanted "I went to a party after work." so on this one I put "I went home after class ended at 3 pm"
Both use the "te" form in the first part, and the "mashita" form in the second part. So what's the difference?