How to write a love sonnate

Do you mean sonnet?

If so you make each line 10 syllables long and follow the rhythm of an unstressed syllable followed by a stressed syllable. Then, arrange the lines into 3 stanzas of 4 lines and end with a 2 line stanza. The quatrains should follow an ABAB rhyme scheme, and the last two lines should rhyme as well.

Select a subject to write your poem about (Shakespearean sonnets are traditionally grounded as love poems).

Write your lines in iambic pentameter

Write in one of various standard rhyme schemes (Shakespearean, Petrarchan, or Spenserian).