Menurut saya, penerjemahan ini tidak akurat. "The lawyer is here already" dalam bahasa Inggris berarti "pengacara itu sudah tiba di sini, dan dia masih di sini", yaitu "pengacara itu sekarang menunggu Anda." Sebaliknya, "pengacara itu sudah di sini" berarti "the lawyer was here", yaitu mungkin pengacara itu sudah berangkat dari sini, jadi dia tidak bisa bertemu dengan Anda. Saya menemui masalahnya yang sama di kalimat Duolingo lainnya... Duo tidak mengerti perbedaan "was" and "is already" (atau "have/has already been").
I don't think the Indonesian translation fully captures the meaning of the English sentence. "The lawyer is here already" in English is very likely to be interpreted as "the lawyer has already arrived here, and he is still here" (i.e. the lawer is here and waiting for you). On the other hand, "pengacara itu sudah di sini" is translated as "the lawyer was here" (i.e. it implies that the lawyer has already left here, so he is not available.) I came across the same flaw in other Duolingo exercises as well. I'm afraid the course developers didn't fully understand the difference between "was" (past tense) and "is already" (or have/has already been; present perfect form).