Lennon starts off the song with “If I fell in love with you…” Fell in this context is incorrect. He had two choices — he could have used the subjunctive mood: “If I were to fall in love…” or the implied future tense: “If I fall in love…” He chose the simple past tense — when coupled with “If”, it seems as if John is uncertain about whether or not he fell. Not the intended meaning, I’m sure.
The implied future tense of “If I fall in love…” make the most sense, both grammatically and rhythmically. Furthermore, it parallels the second and third verses, which start with the implied future tenses of “If I give my heart…” and “If I trust in you…”, respectively.
Many inconsistencies abound in the last verse:
So I hope you see that I
would love to love you
And that she will cry
when she learns we are two
If I fell in love with you
He uses the explicit future tense “will cry” with the past tense “If I fell”. Shouldn’t it be “..she will cry… if I fall in love”? The listener knows that John has already fallen in love with this new girl. But he has to temper his emotions and not reveal his new love to said girl. “If I fall in love…” would have made a good improvement, but “When I fall in love…” would have been the kicker, as would “When I give my heart to you…”, and “When I trust in you…” This makes sense because John predicts that “she will cry when she learns we are two.” Notice he said “when” and not “if”. Choose either the hypothetical “if” or the inevitable “when” and use it consistently throughout the song.