アクセント

　Accent is the pattern of pitch or force used when a word is pronounced.
　How accent works differs greatly from language to language.

　Every single character has its own rise and fall of pitch (a tone).

　Which part of a word is said with more force is fixed (a stress accent).

　As a rule, individual words do not carry an accent of their own.

　Japanese accent is built on pitch — high versus low — and what matters is the place where the pitch falls sharply (the pitch drop).
　In other words, when you listen for Japanese accent, the shortcut to improvement is not hunting for the highest sound, but learning to hear where the drop comes.
　Let's look at a real word. In 「にほん」 (Japan), the pitch falls sharply as you move from 「ほ」 to 「ん」. The drop is therefore right after 「ほ」.

　Now, what about 「にほんじん」 (Japanese person)? Here the position shifts: the pitch falls sharply right after 「じ」, so the drop is immediately after 「じ」.

　The high sound just before the sharp fall is called the accent nucleus.

　A word's accent can be shown visually with marks.
　There are several kinds of marks. The 『日本語発音アクセント新辞典』 published by NHK (the Japan Broadcasting Corporation) currently uses a notation that marks the pitch drop.
　Another way is to show the drop position with a number, such as 「①」 (falls after the first mora) or 「③」 (falls after the third character). It shows the position at a glance, but you rarely see it outside Chinese dictionaries.

　The key rule for understanding Japanese accent is that the first and second mora of a word never have the same pitch.
　In other words, when the first mora is high, the second is always low; when the first is low, the second is always high.

　As you can see, whether the word is short or long, the pitch of the first and second mora always changes.
　With this basic rule in mind, let's move on to the accent patterns.

　Broadly speaking, Japanese accent patterns fall into the flat type, where the pitch never drops partway, and three rising-falling types, where it does.

　Feature: there is no pitch drop at all.
　Tip: say the first mora low, then stay high and flat from the second mora to the end. Even when a particle such as 「が」 or 「を」 follows, the pitch does not drop.

　Feature: the drop comes right after the first mora.
　Tip: say the first mora high, then drop the pitch sharply as you move to the second.
　With the head-high type in particular, letting the pitch fall a little further toward the later characters sounds cleaner.

　In standard Japanese, once the pitch has fallen it basically does not rise again within the same word (some dialects do allow it).

　Feature: the drop comes somewhere after the second mora — but never right after the last kana.
　Tip: say the first mora low, raise the pitch on the second, then drop it sharply right after a character in the middle of the word.

　Feature: the drop comes right after the last mora.
　Tip: say the first mora low, then keep everything from the second mora to the last character high and flat.
　Taken on its own the word sounds just like the flat type, but when a particle (が, を, etc.) follows,
　that particle is said low.

　As a rule, the pitch drop never comes immediately after a special mora (っ, ー, ん). If a word feels hard to say, check whether you are trying to drop the pitch right after a special mora.

　When two or more words join into a single new word (a compound word), the original accent can change.

　However, when the two parts are only loosely joined — as in 「ストレス解消」 (stress relief) or 「暴飲暴食」 (a four-character compound) — each word keeps its original accent as you read straight on.

　There is no clear-cut rule for which compound words change their accent. So when you are unsure whether a compound has taken on a new accent, it is best to look it up in a dictionary and memorize it as it is.

　The accent listed in a dictionary is not always the only correct one. In recent Japanese, words that used to drop in pitch partway (rising-falling types) are increasingly pronounced without the drop (flat type). This is called the flattening trend.

　Either pronunciation sounds perfectly natural in Japan today. As for why flattening happens, it is thought that not dropping the pitch partway (the flat type) uses fewer mouth muscles and is simply easier to say.
　Japanese accent changes day by day, like a living thing. If the Japanese people around you speak with an accent different from the dictionary, that may well be 「real, present-day Japanese」.

　Let's look at words that are read the same but change meaning depending on the accent.
　First work out where the pitch drops, then read them aloud.

　・Japanese has a pitch accent: what matters is not how strong a sound is, but how high it is.
　・The pitch drop is what counts: look for the place where the pitch falls sharply.
　・The basic rule of accent: the first and second characters of a word always differ in pitch. (low→high, high→low)
　・There are four main accent types: the flat type and three rising-falling types (head-high, middle-high, tail-high).
　・Compounds and modern accent: watch out for compound words. Today, flattening of accent is also spreading.