Twenty Fifteen is a lovely example of a single column with a left-hand sidebsr (we've already seen two examples with right-hand sidebars):

In my opinion, sidebars are a must have for your website. They house widgets for all sorts of additional functionality in addition to either the static page or blog roll. A sidebar is a unifying design element because it appears on each page of your website, regardless of any other content.

This concludes the training on Theme Layouts.

In Part 2 of this series, I'll be looking at Themes designed for specific Subjects.