Usually occurring around two thirds of the way through a song, prior to the final chorus, a breakdown sees the musical accompaniment stripped back to simpler rhythmic elements, often with a half time feel, functioning as a dynamic breather before the song's climax.
A passage that links the verse and chorus and acts as a transition between the two, a bridge is sometimes referred to as a pre-chorus. A great bridge builds anticipation and intensity.
The central focus and theme of a song, its calling card and emotional apex. Usually based on the repetition of a simple, direct vocal hook, a catchy chorus is the most important part of any commercially minded song. Use your chorus to make your statement, then explore it within the verses.
The proverbial ear-worm, a hook is an intentionally repeated musical phrase designed to catch the listener's attention. Although a song's main hook is usually its chorus melody, there's no reason why it can't be a guitar riff or any other musical motif.
A distinct "section" of a song, classically but not strictly eight bars in length, the middle eight breaks up the conventional verse/chorus or verse/bridge/chorus pop song structure by shifting gears in terms of the narrative and chord progression. NB: Some people use "bridge" and "middle eight" interchangeably.
Usually a grouping of two or more lines with a set pattern of meter and rhyme - think stanzas, poetry students! Also, the verse often has a narrative storytelling function.