[nickhuh]

In that case you'd want to use "git add -p" which allows you to pick only parts of a file to stage for a commit. It can be crucial in crafting a really solid project / commit history.

For even more complex cases you could use "git add -i"; however, that command can be tricky to work with and I find it's usually not to helpful to get that far into the weeds.

[erichocean]

Atlassian has a nice UI for doing that visually, too. Super easy.

Honestly, people for whom the command line UI is "too difficult" should just use a GUI client. That's the target audience for them.