Remove space between posts

What theme are you using? Can you post a link to your site?

If your theme has a built-in custom CSS option, use it; otherwise, get a custom CSS plugin and put:

#featured-post-11 .entry {
	min-height: 600px;
}

What happened here is that one of your headlines was too long (“Matoshi: Shqiptarët në Maqedoni tregojnë muskuj ndaj shtetit duke u rreshtuar përkrah Erdoganit (Video)”), so it broke the grid. We’re setting the height of each article’s container larger so the grid will remain intact.