For what it's worth, I hear this frequently in Rome, Milan, etc., when someone "rings" the entry control system (cancello). In AE, the equivalents are multiple.: "Someone's at the door," "Hey, Edith! They rang at the door," or merely, "They rang the door." (with other words implied).
There's no such thing as "dropping the have" in English: they're different tenses altogether, they just happen to both match the Italian 'passato prossimo'. I ring, I rang, I have rung: if you wrote "I have rang", that's a grammar mistake (https://data.grammarbook.com/blog/definitions/ring-vs-rang-vs-rung/)
what throws me on a loop here is the word porta, which means door, so my brain wants to say they have knocked on the door, but alas, Duo thinks it should be doorbell, even when my Oxford dictionary translates doorbell as campanello and that word is nowhere to be seen in this exercise.
Hello threlfs. I don't know if I'll change your mind, but for the benefit of any non-native English speakers, or other learners curious about English, who might read this in the future: 'They RUNG the doorbell' isn't a valid translation (because it's not standard English).
'They rung the doorbell' is as wrong as 'They eaten dinner'. Here's why...
Think about the irregular verbs (RING and EAT) in each of their three forms (present, past, past participle): ring, rang, rung eat, ate, eaten
You can use the past tense form of each verb to make sentences in the past tense: 'They rang the doorbell', and 'They ate the dinner'
you can use the past participle with an auxiliary verb (in this case 'have') to make sentences in the present perfect tense: 'They have rung the doorbell', and 'They have eaten the dinner'
YOU CAN'T use the past participle without the auxiliary verb (They eaten...; They rung...) and you can't use the past form with the auxiliary verb (They have ate...; They have rang...)
This kind of confusion is not uncommon with irregular verbs that have three distinct forms (like ring, rang, rung):
go, went, gone; (YOU CAN'T WRITE, 'They gone to the store' or 'They have went to the store') know, knew, known; (YOU CAN'T WRITE, 'They known you were here' or 'They have knew you were here') take, took, taken; (YOU CAN'T WRITE, 'They taken a selfie' or 'They have took a selfie') blow, blew, blown; (YOU CAN'T WRITE, 'They blown a horn' or 'They have blew a horn')
Many irregular verbs have only two distinct forms and use the same form (the same word) for both the past form and the past participle form, i.e. bend, bent, bent; hear, heard, heard; sweep, swept, swept; etc.
With these verbs you can (indeed, you must) use the same word form to make perfectly correct sentences in the past tense and present perfect tense:
They bent the wood, They have bent the wood; They heard the ghost, They have heard the ghost; They swept the floor, They have swept the floor.
Anyway, good luck to all of you in your linguistic endeavours.
Next time try without grammar mistakes; as I liked above, https://data.grammarbook.com/blog/definitions/ring-vs-rang-vs-rung/
Is "they rung the doorbell" fundamentally different enough from "have rung" to cause a wrong answer? I would argue not. So, since I've been moved to the hearts system, I've commented on nearly every BS answer I've gotten wrong due to misleading translations and bad hints, so I'm sure my welcome is wearing thin. But STOP WASTING MY TIME. Jesus Christ
The less colloquial way of saying "they have rung the doorbell" would be "hanno suonato il campanello"; it's quite common, but applies to other bells as well, e.g. when calling for a waiter in fancy restaurants or hotels. The fact that most of them are no longer bells is irrelevant. Ringing something is always suonare, but something ringing could have other translations, e.g. typically "il telefono squilla" (the phone rings), sometimes "il campanello trilla" (trillare refers to the fast intermittent high-pitched sounds some birds make), "mi fischiano le orecchie" (my ears are ringing, literally my ears are whistling) and so on.