(no subject)

[kittydesade]

The は particle indicates the topic of a sentence.

わたしは　アメリカじんです。
てつおさんは　がくせいです。
かねださんは　がくせいです。
アンンアさんは　しゅふです。

In more complex sentences we'll generally begin with []は and follow it up with a long string of words connected by particles, followed by a verb. Right now with what we know we're limited to [subject]は [noun]です.

せんもんは　なんですか。
いまは　なんじですか。

The particle か (ka) at the end of the sentence, as a suffix onto the verb, indicates a question. This is pretty much the only thing you have to do in order to form a question in Japanese.

なん (nan) and　なに (nani) are forms of 'what'. This, plus the particle ka, make up a large number of the questions we will be dealing with initially.

せんもんは　なん　ですか。 [senmon]wa [nan]desu-ka.
いまは　なんじ　ですか。 [ima]wa [nan]ji desu-ka.

Here we have a noun followed by a topic marker, which indicates the topic of the sentence, followed by the derived form of 'what'. In the first example it is a plain what, and in the second example it has the following noun 'ji', meaning 'hour. So a literal-ish translation of these sentence is:

[Speaking of] Your major, what is it?
[Speaking of] Now, what hour is it?

You can also ask the time as　なんじ　ですか。[nan]ji desu-ka.

なんねんせい　ですか。[nan]nensei desu-ka.

Here there is only one noun grouping plus the copula verb, so it is a very simple question form. And because the "what" is followed by a noun, we know that the speaker is asking about the noun and it does not require the topic marker, as in "What hour is it."

What major is it? [here 'it' means 'yours,' or the person the speaker is addressing. Remember, Japanese omits many words it feels are indicated sufficiently by context.]

アメリカ人　ですか。[amerikajin] desu-ka.
がくせい　ですか。[gakusei] desu-ka

Finally, simple yes or no questions are indicated with [phrase being questioned] desu-ka. For example here: Are [you] an American? Are [you] a student?