Which of the following lines from "Out, Out-" deviates from iambic pentameter?

And nothing happened: but the day was all but gone

The correct answer is - So. But the hand was gone already.

An iambic pentameter is a way of writing poems that Shakespeare often used. Iamb means that there are two syllables, the first one being unstressed, and the second one is stressed. If you take a look at the line above, you will see that - so (unstressed), but (stressed), the (u), hand (s), was (u), gone (s), al - (u), ready (s).

Pentameter refers to the number of syllables in one line. A meter consists of 2 syllables; penta means 5. If you combine those two, a pentameter means that there are 10 syllables in each line.

The line So. But the hand was gone already has eight syllables, and therefore isn't a pentameter (but it is iambic).