There are several ways in Russian to express the idea of “the same” in the sense of “the same house” or “the same country.” One way is to use один (which is also used as a cardinal number), and another way is to use «тот же». For instance, if you are just starting a conversation, you could say:

Oddly enough, in that context you cannot say «в том же доме». What's the difference? Essentially it's this: in order to use «тот же» the noun must have previously been mentioned in the conversation. For instance:

Another example. If you are for the first time mentioning your transportation over the weekend, you might say:

But if you have already mentioned the train car, then you use the other phrase:

Of course, the phrases can be used in other cases as well:

Sometimes один and тот же combine into a single phrase «один и тот же», but we'll save that phrase for another time.

Ходить is the most generic word in Russian that means “to go.”

Because it implies travelling under one's own power (that is, not using some device or animal for transportation), we often translate it “to walk”:

The verb is also used in sentences where someone regularly goes somewhere.

The verb is also used to describe the motion of someone walking around a place with no set goal or direction, e.g. walking around a park for pleasure, walking around the city, or going here and there among shops:

Last but not least, the verb is used to indicate a single round-trip in the past. In this usage it implies that the person is no longer at the place mentioned.

Russian verbs of motion have the reputation of being quite difficult. Certainly they take some practice, but if you just calmly, slowly, and methodically work on them, particularly identifying what contexts they are used in as we did here, then you can certainly master them.

Here is a list of the fifteen verbs of motion. They are usually taught in verb triplets, not pairs. If you want to work on these verbs, I suggest Muravyova's “Verbs of Motion in Russian” if you can still get it, and also William Mahota's “Russian Motion Verbs for Intermediate Students.”

The next use of the word на with the accusative case is equivalent to the English word “by” in contexts where you are comparing one thing to another.

That last example brings us to an interesting point. When you are counting differences in numbers of people, you get the following quirk with the numbers two, three, and four:

If this were the true accusative after на in this meaning, we would expect «на двух человек» or «на двоих людей», not «на два человека». Other examples:

This shows us one of two things: either a) the accusative case is not entirely stable in modern Russian, or b) на in this meaning actually uses a separate case that is minimally distinct from the accusative. I argued for the latter in my doctoral dissertation, although the former is probably true as well.

¹ Yes, I know that the “correct” way to say it is “I'm older than he,” but any normal American is going to say “I'm older than him.” It's time for the pedants to catch up to the living language: “than” has become a preposition in such contexts.
² Yes, I know that the “correct” way to say it is “eleven wives fewer,” but normal people don't talk that way. It's time for the pedants to catch up to the living language: “less” is perfectly normal these days when dealing with count nouns.

The next use of the word на with the accusative case is equivalent to the English word “for” in some contexts. For instance, when you are talking about what you ate for a particular meal:

When you put aside money for a particular purpose, на plus accusative also works:

The second meaning of the preposition на is “on” in the sense of “onto.” In this meaning it is complemented by the accusative case.

¹ Двор and neighborhood are not really the same thing, but for this example it should work.