Answer and explanation:
"Once By The Pacific" is a poem by author Robert Frost. We can tell the poem is a sonnet due to the way it is structured. Sonnets have 14 lines and a regular rhyme scheme. Also, they usually maintain a strict metric, commonly iambic pentameter - a five-time repetition of an unstressed syllable followed by a stressed one in each line. "Once By The Pacific" has all those characteristics:
The shattered water made a misty din. A
Great waves looked over others coming in, A
And thought of doing something to the shore B
That water never did to land before. B
The clouds were low and hairy in the skies, C
Like locks blown forward in the gleam of eyes. C
You could not tell, and yet it looked as if D
The shore was lucky in being backed by cliff, D
The cliff in being backed by continent; E
It looked as if a night of dark intent E
Was coming, and not only a night, an age. F
Someone had better be prepared for rage. F
There would be more than ocean-water broken G
Before God’s last Put out the light was spoken. G
As we can see above, the poem has 14 lines and its rhyme scheme is Shakespearean - AABB CCDD EEFF GG. Let's take a look at the first line to confirm the metric:
The shattered water made a misty din.
Iambic pentameter is used. The syllables in bold are the stressed ones. We have 5 pairs of unstressed followed by stressed.
Also, in lines 2-6, water and clouds are personified. Personification is a type of figurative language used to attribute human characteristics - qualities or action - to inanimate objects. The water is described as something that can look and think, while the clouds are described as locks of hair being blown.