Intro (chorus) 0:00-0:05
Verse 1 0:29-0:36
Verse 2 1:00-1:08
Verse 3 1:31-1:39
Comments: Technically speaking, "Wait" has a 2-part intro. The piano plays, then the rest of the backing instrument join in before the vocals enter. However, in this case the piano playing at the start is so brief that I cannot consider it a separate part. Rather, the piano notes at the start are merely pick-ups, and thus "Wait" does not have a 2-part introduction. ( "What Goes On" features the same thing except with guitar instead of piano.)
Many Beatles tracks to date ( "A Hard Day's Night",  "Things We Said Today",  "I Don't Want to Spoil the Party",  "No Reply",  "Eight Days a Week",  "I Need You",  "The Night Before", and  "I'm Looking Through You") have employed verse structures in which the third quarter is noticeably different from the other three quarters. "Wait" pulls a similar trick, but this time in the chorus:
Say the word and you'll be free, Say the word and be like me.
Say the word I'm thinking of, Have you heard the word is love.
It's so fine, It's sunshine,
It's the word love.
The first, second, and fourth lines are very similar, with the third line providing a brief contrast.
Lastly, the coda of "Wait" is intriguing. At 39 seconds, its duration is one of the longest coda on a Beatles track to date - only 3 other tracks are of roughly equal or longer length: [13f] "Please Mister Postman" (49 seconds), [13c] "Money (That's What I Want)" (48 seconds), and [29b] "Long Tall Sally" (38 seconds). (Interestingly enough, all of those are covers - not originals.) Because of its length, the coda has distinct subsections: The verse is heard but with backing instruments only (no vocals), followed by the chorus with greatly simplified lyrics ("Say the word love, Say the word love, Say the word love, Say the word love"), followed in turn by another iteration of the verse without vocals which fades out.