Because I could not stop for Death is full of iambic meter. This is ironic because the poem is about death and chooses to use the meter of the hearbeat.

She's too busy for Him (Death), so in a sense when Death stops for her, He literally stops. He does not take her life, and she maintains immortality.

Emily Dickinson personifies death with a gentleman caller. (Prof. Abrahamson)

Emily Dickinson uses assonance, the repetition of certain vowel sounds, to emphasize the slow drive. It gives the line, as well as the poem, a dragging feeling. This is further felt thru use of enjambment, in which the poet uses dashes to create long segments of pause. (Prof. Abrahamson)

The quickness of this line contrasts and thereby further emphasizes the slowness of Death.

She is drawn to him by his civility. This reference to his politeness further personifies death with a gentleman caller. Perhaps even convention is beyond the grave.

Strove - To struggle (Webster's); This is an odd idea: children are struggling to play. Fun doesn't come naturally; people have to work for it. She shows how people do not really enjoy life while they still have it.

Death takes her on a ride to view her past: it takes her through her youth, middle age, and old age.

The use of this word is ironic in that the correct word is grazing, which makes one simultaneously think of both words. It acts as a metronome, giving the sense of infinity. (Prof. Abrahamson)

She continues to give the sense of endlessness. Even while they are riding around, everything seems to pass them by. But in the same moment in the theme of endlessness they are both moving and standing still. As for the sun passing them by it is also because they have stopped; they have come to their destination, the cemetary. Her senses are now exposed to other more uncomfortable feelings.

She plays on this word as it sounds like shivering; here it implies fright. (Prof. Abrahamson)

Gossamer - Very light weight material (Webster's); she is apparently in her nightgown; this shows she is clearly unprepared for Death; she had been in control up to this point.

Mausoleum (Prof. Abrahamson)

Repetition of line 18 - She moves the reader toward a vision of where she's heading.

Enjambment is used here to show separation from life to death.

It took a long time arriving to Death because she didn't know where she was going. But now in retrospect, it didn't really take any time at all.