When an author carefully chooses her words, she is using Diction. Diction are emotionally-charged words which the author chose herself
The answer is in the statement: <span>This is a stylistic device where the writer repeats the same word or phrase for the purpose of emphasis.
Therefore, the answer is repetition.</span>
to make sure you can cite id correctly if needed
Because a sonnet is a love poem as such, therefore they speak this way to convey a sense of passion and also lust, it is effective as it is a love poem as i mentioned, therefore it is self explanatory