Этого is genitive case (required after возле) of это

Just in case this helps: http://www.russianlessons.net/grammar/pronouns.php

As stated, этого is a genitive case of это. You can find prepositions that require genitive case here: http://www.departments.bucknell.edu/russian/language/prepgen.html

Возле is one of them. Hence возле этого.

I was wondering the same thing

Russian doesn't have a word for "the". Although sentences using этот can sometimes be translated using "the," you never need to. Offering that as a possible translation, while technically accurate, probably is contributing to confusion.

этот always means "that" or "this," in the sense of "the one we're talking about."

It's probably worth reporting this. It seems like this one of the inconsistencies you sometimes see with Duolingo where the scrolling offers you several translations and then marks you wrong for using one of them! I suppose it's partly because Russian is still in Beta phase. This shouldn't stop us from realising what a brilliant course this is however!

It used to be difficult for me to distinguish between Анна и она as well. Анна is stressed on the first А and with она the stress is placed on the second а.

With the difference in stress, it's almost like they say она as uhNA and Анна as Annuh.

For historical reasons related to Old Russian. That is the correct pronunciation whenever you see -ого.

i think you have to mention the name

Russian doesn't differentiate between definitiveness and indefinitiveness in nouns. это mean this, but it can also be translated as the (and if I remember correctly also that) depending on the situation. In this Duo course they've made the decision of mostly translating it to this. On the reverse tree, I think; it's mostly translated as the.

This confusion is due to the fact that languages work differently. Whenever a category is missing in a language like this, it's impossible to say a word has the same meaning as in another language where the category excists. It's good to compare, it's even better to learn to look at the world through the new language.

They are all different noun cases of этот. Are you reading the "Tips and notes" section of the various courses? Make sure to read the sections for at least the following courses: Where, Genitive1, Accusative, Prep&Place.

Your comment seems incorrect to me. 1. You would say "Anna is near the taxi" only if a specific taxi was previously discussed. If you haven't talked about some taxi prior to this sentence, referring to "the taxi" would raise questions. 2. Say there's only one taxi, and it's a 100m away, pointing at it and saying "this taxi" is bad English. Proper English is to address it as "that taxi", and there would be no exclamation whatsoever in this context. By the way, in the meantime I've actually realized that the two concepts in fact exist in Russian, they are этот and тот.

Genitive. "возле этого"

Ferrum already answered this: "For historical reasons related to Old Russian. That is the correct pronunciation whenever you see -ого."

OK, I understand now that "this taxi" is "этот такси" and "that taxi" is "тот такси". Is this correct?

No, because then you would have something in past tense to let you know.

далеко means far but you still need to translate "from" as "от". That is also genitive so the rest of the sentence is the same.

It's a little quirk in Russian pronunciation. All of these genitive endings -его and -ого have a v sound.

Yes

Here is a good resource on genitive case that will get you started. The entire website is a great companion for Duo — I especially appreciate it as a resource on perfective and imperfective verbs, when you get to that point.

http://www.russianlessons.net/lessons/lesson10_main.php

And the short answer is the genitive case in English is words with "of" before them or with an -'s ending. Russian also has some words like возле, для, у, нет, where the next word has to be genitive.