The import of this sentence is that it demonstrates how the meaning changes -- sometimes with
subtlety -- based on the placement of
emphasis on any single word in the sentence:
I never told you she stole my heart.
(Whoever it was you heard that from, it wasn't me!!)
I never told you she stole my heart.
(Sorry bud, but in response to your proposition, that utterance simply did not escape my lips. Ever.)
I never told you she stole my heart.
(Yep, she stole it; but I kept that bit of information, ahem, close to my chest.)
I never told you she stole my heart.
(Oh, I told everybody else; but you-- you, I kept in the dark.)
I never told you she stole my heart.
(Somebody had done so, I let you know that much, but did I mention it was her who done it?)
I never told you she stole my heart.
(I'd let you know she'd gotten hold of it somehow-- but not by thievery!!)
I never told you she stole my heart.
(I let on that she was a heart-stealer; just never that mine was amongst the ones which were stolen....)
I never told you she stole my heart.
(Perhaps you thought it was my wallet that she stole? my identity? a kiss?)
In addition to all these variations, the whole sentence recited without emphasis on any one word is equally diverse in meaning if spoken with a sly smile, or with a sad, slightly distant gaze into the point of nothingness just over your left shoulder, or with an angry bark, or with a jackal's laugh. Notice as well that interposition of a grammatically correct 'that' in the sentence (as in 'I never told you that she stole my heart') breaks the series, for a sentence emphasizing that word ('I never told you
that she stole my heart') would simply be weird and distracting to the point of losing its meaningfulness.