Question

Which sentence contains correct capitalization?   When dry-stacking a stone wall, you need these items: a stonemason’s hammer, gloves, flat stones, and gravel. When dry-stacking a stone wall, You need these items: a stonemason’s hammer, gloves, flat stones, and gravel. When dry-stacking a stone wall, you need these items: A stonemason’s hammer, gloves, flat stones, and gravel.

Answer 1

The first sentence is punctuated correctly.

Answer 2

The answer is: When dry-stacking a stone wall, you need these items: a stonemason’s hammer, gloves, flat stones, and gravel.

Two observations. First, every sentence needs to start with a capital letter.

Second, the word that follows a colon, that is the symbol characterized by two dots on the same vertical line, is written in lower-case, unless it needs to be capitalized for some specific reason like the word being a proper noun or an acronym.

A colon basically means “that is to say”.