Definitions

Stressed mora

It's the last high mora before a downstep. Note that if there's no downstep (heiban), the final mora is not stressed. In this wiki, stressed moras are marked in red. Examples:

• せんせい (先生) - せ is the last high mora, so it's stressed
• アニメ - ア is the last high mora, so it's stressed
• はな (花) - な is the last high mora (the downstep is still there because it's odaka)
• わたし - no stressed mora (し is the last high mora but there's no downstep after it)

An expression "X is stressed" is equivalent to "X is a stressed mora", and by extension "X is the last high mora and after it there's a downstep"

Stressed word/phrase

It's a phrase which has a stressed mora. In practice, heiban is consider non-stressed and atamadaka, nakadaka, and odaka are considered stressed

Weak mora

It's a mora which cannot be stressed, even if it otherwise would following the regular rules. っ and ん are never stressed and therefore are considered weak. Additionaly, for some long vowels/glides the second mora is considered weak, but it's not always the case. Examples:

• せんせい (先生) - ん and い are weak moras
• おおい (多い) - the second お is a weak mora as it's the second mora in the long o
• かえる (帰る) - え is a weak mora as it's the second mora of the ae glide

In almost every case, when a weak mora needs to be stressed, the stress moves one mora back:

• しゃかいじん (社会人) not しゃかいじん, because い is a weak mora