"I had arrived a few minutes before."
Translation:Yo había llegado unos minutos antes.
Agreed, Duolingo freely accepts either yo or el/ella in literally hundreds of situations. While I know where Frank (above) is coming from (my first teacher in Bogotá insisted that I always use the pronouns) the use of pronouns is nearly always optional. I've reached the end of this course and have gotten over 500 crowns and missed lots!!! of questions. But never for not putting a yo in there...
Hi Shirl, You have to use 'yo' because 'habia llegado' could mean 'I had arrived or he/she had arrived. When you use 'yo' it means 'I had arrived'. I would explain the difference between 'yo' and 'me' this way. 'Yo' is the subject pronoun ie I want = yo quiero, or I ran = yo corri. 'Me' pronounced 'may' is the the indirect object pronoun ie he called (to) me = el me llamo. In English it comes after the verb, in Spanish it comes before the verb. Hopefully this explains it, I am not a teacher but have been studying Spanish for a few years now but don't usually explain things very well.
Because había llegado is not Preterito Imperfecto (Imperfect) and hube llegado is not Preterito Indefenido (Simple past). had arrived is Past perfect which translates into Pluscuamperfecto => había llegado. Of course, there is a Preterito anterior => hube llegado, but it's almost never used in Spanish and really difficult to explain in a short comment.
The problem is that the word "arrived" in English can mean two things. It is the simple past tense form of "to arrive", but it also is the past participle of the same verb. In English these are spelled the same for some words, but in Spanish they never are.
Take the English word "eat". For past tense we say "he ate" but we don't say "he had ate", it's "he had eaten". For this verb, the two forms are different. For "arrive" they are the same, which can cause confusion in translations like this. Another English example is "he fell" but "he had fallen" (not "he had fell"). In Spanish the simple past tense and the past participle will always be different.
So if you make a past compound verb in Spanish like we are doing here, you must always use the past participle, which will in regular verbs end in -ado or -ido -- although there are a lot of verbs that are irregular in the past participle. One example of an irregular that you will see on a daily basis in Spanish-speaking countries is for abrir (to open). If it were regular it would be "abrido" but the proper past participle is "abierto" which you see displayed in shops everywhere to show the shop is "opened". :)