What techniques are utilised to portray the 'change' in "The Road Not Taken"?

What change is it that you are refering to in this great
poem? Do you mean the way in which the final stanza suddenly projects the speaker into
his own imagined future when he will look back and think of the choice he made? I will
assume this is the case, but please respond to my answer if I have not understood your
question correctly.

Let us focus on the final stanza and
its content:

readability="15">

I shall be telling this with a
sigh

Somewhere ages and ages
hence:

Two roads diverged in a wood, and
I--

I took the one less travelled
by,

And that has made all the
difference.

I think one of
the major techniques that is used in this final stanza is that of repetition. Note the
way in which the third line is basically a copy of the first line of the entire poem.
This of course helps to conclude the poem but also leads towards the way in which this
is a momentous decision that the speaker has to make. It helps us focus on the way in
which this one decision has "made all the difference" in terms of the future of the
speaker's life. Choosing the path "less travelled" has resulted in one specific kind of
future, whereas, it is suggested, if he had taken the other path, he would have had a
different kind of future.

The use of the word "sigh" in
this last stanza greatly interests me. It seems to point towards a kind of introspective
rumination about the kind of life that the speaker would have experienced had he
selected the other path. The title of the poem, focusing on "The Road Not Taken,"
likewise reinforces this view. To me, this captures the way in which we can often find
ourselves haunted by the decisions we have taken in our lives and the way that they have
resulted in our present realities. Major life decisions like not marrying or marrying
somebody, moving to a different city to take a job or refusing such an opportunity could
radically impact our lives, just like the two paths that lie before the speaker. Perhaps
the final stanza indicates a change of tone to a more introspective, meditative
wondering about different possible futures that the speaker could have enjoyed, but at
the same time sadness regarding the way that such alternative futures have been
irrevocably lost with the choice of one path over another.