There are lots of different ways to write a sonnet, which is basically just a particular kind of short poem. Shakespeare's sonnets have a very specific form, which McKay borrowed in "If We Must Die." Shakespearean sonnets have several things in common:
They are 14 lines long.
They are written in iambic pentameter. Before you fall asleep at your computer, let us explain: "iambic" refers to the pattern of unstressed and stressed syllables. One iamb is an unstressed, followed by a stressed syllable: da-DUM. "Pentameter" tells you how many iambs you'll find per line. "Penta" means five – so there are five iambs per line. Iambic pentameter. Here's an example from the first line: If we | must die|, let it | not be | like hogs
Usually, they include a feature called a "turn." This is a moment in the poem where the theme or the tone changes in a surprising way. In "If We Must Die," the turn comes at line 9, where the speaker calls his kinsmen to action: "O kinsmen! we must meet the common foe!"
The first twelve lines rhyme in alternating pairs. To show how this works, we can assign a letter to each rhyme. We'll show you how it works for the first eight lines:
If we must die – let it not be like hogs (A) Hunted and penned in an inglorious spot, (B) While round us bark the mad and hungry dogs, (A) Making their mock at our accursed lot. (B) If we must die – oh, let us nobly die, (C) So that our precious blood may not be shed (D) In vain; then even the monsters we defy (C) Shall be constrained to honor us though dead! (D)
For the whole poem the rhyme scheme would be: ABABCDCDEFEFGG.
See those last two letters at the end (the GG)? That's the last important thing to know about the form of a Shakespearean sonnet. They always end with two rhyming lines, one right after the other. We call this a rhyming couplet. Here's the couplet from the end of "If We Must Die":
Like men we'll face the murderous, cowardly pack, (G) Pressed to the wall, dying, but fighting back! (G)