Deceptive cadences refer to a particular pattern of chords in which the chord built on the fifth scale degree, which usually resolves to the first scale degree, instead proceeds to the sixth scale degree. This may be expressed in roman numerals as follows:
Deceptive V-vi (or, less commonly, V-bVI)
One of the defining characteristics of a deceptive cadence is the aural anticipation of tonic following the dominant chord. That expectation is then thwarted, thus the term "deceptive".
Additionally, cadences by definition conclude phrases. Deceptive cadences, then, may only be found at the ends of phrases. Many Beatles songs ( "There's a Place",  "Thank You Girl",  "She Loves You",  "And I Love Her",  "Any Time At All",  "I Don't Want to Spoil the Party",  "Ticket to Ride",  "Yes It Is",  "You Like Me Too Much",  "Drive My Car",  "We Can Work it Out",  "I'm Looking Through You",  "A Day in the Life",  "She's Leaving Home",  "Glass Onion"  "The Continuing Story of Bungalow Bill",  "Something",  "Her Majesty", and  "Because") use the same chords that would be used in a deceptive cadence, but these are not actually so because they bridge phrases (with V concluding the former phrase and vi starting the new phrase) rather than conclude them (with V-vi concluding the former phrase and the new phrase beginning on some other chord).
Conversely, some songs ( "I Want to Hold Your Hand",  "I Should Have Known Better",  "Tell Me Why",  "I'm Happy Just To Dance With You",  "I'll Cry Instead",  "The Night Before",  "In My Life",  "For No One",  "Strawberry Fields Forever",  "When I'm Sixty-Four",  "With a Little Help From My Friends",  "All You Need Is Love",  "Hello Goodbye",  "Piggies",  "I'm So Tired",  "Let It Be",  "Oh! Darling",  "Polythene Pam") use the right chords in the middle of their progression - rather than at the end as part of a cadence.
More unusually,  "Eight Days a Week" uses the same chords not as V to vi, but as bVII to i during a tonicization of the relative minor during the Middle 8; and  "Sun King" uses the chords, but in a non-functional harmonic context.
All of these instances are not examples of deceptive cadences and are thus purposely omitted from the list below. With those out of the way, 7 Beatles songs actually do employ true deceptive cadences, and each is identified below with analysis and explanation.
 "P. S. I Love You" uses probably the most blatant of all the Beatles' deceptive cadences a total of four times (0:25, 0:43, 1:15, 1:47), each iteration using the same lyrics and chords.
A Bb C D
P. S. I love you, you, you, you.
V bVI bVII I
Deceptive cadences, as their name implies, are deceiving by nature. But this particular deceptive cadence draws further attention to itself by proceeding from V to bVI - a strikingly foreign chord in D major. In a textbook example of a deceptive cadence, the insertion of this bVI extends the phrase (from what would have been 8 bars to 10) and delays the eventual resolution to I.
 "Do You Want to Know a Secret" uses the five iterations of the same deceptive cadence: 0:38, 1:05, 1:43, 1:47, 1:51 - the first three of which come at the end of each verse; the last two coming in quick succession as part of the song's coda, which fades out as the cadence repeats.
F#m B7 A B7 C#m
Say the words you long to hear: I'm in love with you.
ii V7 IV V7 vi
This deceptive cadence also extends the phrase and delays tonic by two measures.
 "Not a Second Time" uses a total of three deceptive cadences (0:41, 1:01, 1:47), the first and last of which are to identical lyrics sung by Lennon . . .
Am Bm D7 Em
You hurt me then, You're back again, No no no, Not a second time.
ii iii V7 vi
. . . while the middle cadence is during the solo, which employs the same melody and chords as the outer deceptive cadences, just played by a piano instead of sung by Lennon. In all three instances, the deceptive cadences replace resolution to tonic (rather than delay resolution to tonic, as was the case with "P. S. I Love You" and "Do You Want to Know a Secret".)
 "When I Get Home" is the jackpot for Beatles songs that use deceptive cadences. With a total of nine iterations of four unique progressions, it uses more deceptive cadences than any other Beatles tune.
The first (the most frequent with four occurring at 0:12, 0:42, 1:13, and 1:47) appears near the conclusion of each chorus with identical lyrics and chords each time.
D7 G7 Am
I got a whole lot of things to tell her when I get home
II7 V7 vi
The next-most-frequent, with three instances occurring at 0:31, 1:01, and 1:51, appears near the end of each verse, with identical chords but different lyrics each time.
C F7 G7 A
I've got a whole lot of things I've got to say to her. Woah-oh-oh-ah
I've got a girl who's waiting home for me tonight. Woah-oh-oh-ah.
I've got no business being here with you this way. Woah-oh-oh-ah.
I IV7 V7 VI
These deceptive cadences vary slightly from the previous examples (from the same song) because while they both feature G7 (V7) chords followed by chords based on A, the former uses A minor while the latter uses A major.
The last two instances are both unique in the song. At 1:32, near the end of the Middle 8:
F G7 Am
till I walk out that door again.
IV V7 vi
The final deceptive cadence, occurring at 2:02, is identical to those four occurring at 0:12, 0:42, 1:13, and 1:47 except for the final chord, which is major instead of minor. In this way, this cadence may be viewed as a combination of the previously heard deceptive cadences, with the purpose to propelling the song to its conclusion.
D7 G7 A
I got a whole lot of things to tell her when I get home
II7 V7 VI
In all nine instances of deceptive cadences in "When I Get Home", the deceptive cadence expands the phrase and delays the resolution of tonic.
 "Ob-La-Di Ob-La-Da" uses just one deceptive cadence (2:58) but it's also one of the more obvious in the Beatles repertoire because by the time we hear the deceptive cadence, we have already heard it as an authentic cadence (V to I) 3 times (0:42, 1:16, 2:07). In explicit and definitive terms, then, this deceptive cadence serves to prolong the phrase and delay the resolution to tonic.
Bb Dm/F Gm7 Bb F7 Gm
Ob-la-di Ob-la-da Life goes on bra, La la how the life goes on.
I iii/5 vi7 I V7 vi
In  "I Will", all four deceptive cadences are saved for the end of the song. The final verse substitutes vi for I three times (1:11, 1:15, and 1:20), prolonging the phrase and delaying tonic resolution - but not before the really attention-grabbing deceptive cadence at 1:25, which pulls the same stunt (V to bVI) McCartney used way back in "P. S. I Love You".
Bb C7 Dm Bb F (Fdim Gm C7 Db7)
Sing it loud so I can hear you
Make it easy to be near you
For the things you do endear you to me and you know I will
IV V7 vi IV I i* ii V7 bVI
 "Octopus's Garden", just like "I Will", saves both of its deceptive cadences for the coda (2:34, and 2:39).
A B C#m A B C#m
In an octopus's garden with you. In an octopus's garden with you.
IV V vi IV V vi
Both of these deceptive cadences prolong the final verse, propelling the son to its conclusion, and delay resolution of tonic.
OBSERVATIONS & CONCLUSIONS:
1963: 2 ( "Do You Want to Know a Secret",  "Not a Second Time")
1964: 1 ( "When I Get Home")
1968: 2 ( "Ob-La-Di Ob-La-Da",  "I Will")
1969: 1 ( "Octopus's Garden")
This blog is a workshop for developing my analyses of The Beatles' music.