Translation:The class has already started.
Hahaha. I started writing "class has already started" and was like, no, you're going to hate me because that's not literal enough, so I put "class is already starting", but it was marked wrong and said my original answer was correct.
ている is not always the continuous tense in English though. It is for verbs that describe an action (i.e. eating, drinking etc) but for verbs that describe a change, the ている form implies that the change continues. So, since "to start" describes a change, はじまっています describes the continuation of having started = "has started". The same is true for example for verbs like dying (死ぬ), which also describes a change, where 死んでいる does not mean "is dying" but "has died". So in a way, your first answer is a literal translation. There is of course also context needed since some verbs can both describe a change and an action (smelting for example).
Yes, I understand that. I'm just laughing because I was trying to out-smart Duolingo's sometimes pedantic stringency for literalness and ended up out-smarting myself in the process.
thanks Bryan, I came to the comments wondering why it was ます instead of ました
You can use the adjective 瀕死 (ひんし), which means "dying" or "on the verge of death".
私は瀕死です。- I am dying.
Translate it as "class has already started", have it marked as incorrect because it must be "the class has already started". Even though the Japanese version contains no article of any kind, and the English is perfectly correct without one too.
is the particle "The" necessary in this translation? I was marked wrong for omitting it.
もうじゅぎょうははじまっています。 The answer I submitted and the correct answer listed match, but the question was still counted as incorrect. There was not a report option available for this error.
The います here is part of the conjugation for the present-continuous tense はじまっています "is starting" or in this case "has started" as explained in the above comment by KiritsuguZFC, it is used for an action that is ongoing and can be used with transitive or intransitive verbs.
あります is for the existence of something, but there is a -te arimasu verb form. It is used differently to the -te iru form. (I don't believe Duo currently covers this conjugation yet). The -te aru form is used with only transitive verbs to describe intentional actions with an ongoing affect. Something intentionally being done to an object with results that are still in effect. If you'd like to know more about it there's a nice guide by Maggie-sensei
An example comparison between the two forms she gives is
窓が開いている - mado ga aite iru - The window is open (the window was opened and continues to be in a state of being open) Subject + ga/wa + Intransitive verb (aku) + Iru
窓が開けてある - mado ga akete aru - The window is kept open. (It was intentionally opened by someone and is still being kept open) Subject + ga/wa + Transitive verb (akeru) + Aru