You might see a post that is so funny, amazing, asdfghjkl; [asdfghjkl; is a common expression in the world of Tumblr], etc, that you absolutely have to have on your blog.
Well, no worries. Tumblr provides you with a lovely way to do that, the...
If you're on someone's blog, the reblog button will be a black button on the top right that says 'reblog' .
This will then take you to a screen where you can add anything to the post, or tag it, if you'd like.
When you want to post it, you click the 'reblog post' button on the bottom left.
If you're on your dashboard, you will see a symbol that's two arrows pointing in different directions that form a rectangle on every post. Simply click that, and you will be taken to that same screen.
If you hit alt+reblog, it automatically posts it to your blog, without taking you to the other page.
If you hit ctrl+reblog, it opens the page in a new tab.
Now, as kids these days say, isn't that rad?
...wait. Am I still behind the times?
What do you say nowadays? That's so jokes?