Wa-t the Heck
As was mentioned the previous day, Japanese doesn't have spaces between each of the words. Instead, words are divided and marked with particles. Particles are similar to words, except that they don't have meaning inherit in themselves alone. They are only written in Hiragana and mark certain parts of speech; they can function as modifiers, connecters, and markers within just about every Japanese sentence. From this point on we will approach Japanese like a puzzle, and we will use these particles as keys to understand how all the pieces fit in Japanese sentences.
The first and most important particle is Wa/は. Wa marks the topic of the sentence. That is what you are talking about. In other words, the most important thing in the sentence.
Now your first thought after seeing 'wa' is probably that は the symbol for 'ha' not 'wa' – and you would be right. However, this is one of two Hiragana that have alternate sounds. When 'は' is used as a particle it is pronounced 'wa'. The best indicator we have to differentiate whether it is 'wa' or 'ha' is to check its location and function within the sentence. If は is found within a word, it is most likely pronounced 'ha', if it is found outside of a word or between two words it's most likely pronounced 'wa'. Particles follow that which they are marking. So, は can be more easily identified as a particle when you see it following a noun or phrase.
[Particle] は (wa) is one of the most fundamental particles in Japanese. It is used for a few different purposes, but it is primarily used to introduce or identify a topic in a sentence. It is important to note that the は and preceeding subject/topic can be excluded from a sentence, however, they are only omitted when those in the conversation already know what the topic of the conversation is. This is extremely common in Japanese. (Almost never happens in English.) This can be quite confusing, but probably the best advice to beginners is to try to catch the topic of the sentence at the beginning of the conversation (or paragraph in writing), and unless the topic is reestablished or changed by another は the topic will remain the same.
In a SOV (Subject -> Object -> Verb) language the は particle marks the main subject (S) or topic of the sentence. (The subject can also be marked by Ga/が, but we'll get into that later.)
Another important point to note is that は cannot be used in sentences following “WH” question words… (“Who?” “What?” “When?” “Where?” “Why?” and “How?”). The list is more expansive in Japanese, so all “WH” question words will not be listed here. However, a few of these are: 誰(dare), 何 (nani), いつ (itsu), なぜ (naze), and どうやって (douyatte).
は is almost always at the beginning of the sentence, and will mark the most important part of the sentence.
Japanese is a hierarchical language. Meaning that it has levels of respect and formality. You speak more respectfully to your boss than your little sister, and you speak more formally to your teacher than your best friend. The first step to formality and addressing people correctly is to address people with an appropriate suffix. Suffixes connect to an individual's name, first or last (the first name is the family name and the last name is the person's given name) either can be used depending on how familiar a person is with the person they're talking about. First names and either -san, -kun, or -chan are used less frequently, and only by those who are very close or familiar with the person they're addressing. Last names are used more frequently, followed by -san (the most frequent), -sama (usually only used nowadays when speaking to customers or when showing an extreme amount of respect), or -sensei (if they are the person's teacher, professor, or mentor), but names in Japanese must always be followed by a suffix of some sort.
Below are the 5 most common suffixes.
San is used . This is often translated as Mr. or Ms. and can be used with anyone that isn't your friends or family. This is the most commonly used suffix.
Chan is used for someone young, usually women. You can use it for men, but usually only your boyfriend or someone who is quite a bit younger than you, like a child.
Kun is similar to Chan in that it is used for someone who is typically younger than the speaker, but more often used for someone boyish or male. Not always, but generally. A general rule is that kun can be used with those younger than the speaker (when the speaker doesn't intend on showing respect), or with someone who is the same age, male, and has a familiar relationship with the person speaking.
Sensei is used for someone knowledgable or who is a teacher, professor, or mentor. This can be a classic teacher or even a doctor or lawyer. Basically someone who deserves respect and is teaching you. Hence Manga Sensei is “Comic Book Teacher”.
Sama shows the highest amount of respect, and should only be used to address the most respectful of persons. Presidents, Gods, and High Officials. This is often used with customers of a business or establishment. However, using this with people who don't actually deserve this much respect will come off as extremely sarcastic and will have the adverse effect of being a slight or an insult.