Alyson Hannigan struggled to master the difficult language of Low German for her new role in TV show Pure.

The 45-year-old actress stars as Esther Dunkel in the hit U.S. programme, which tells the real-life story of the 'Mennonite Mob' that trafficked cocaine across the Canadian border. The role is something of a departure for Alyson and, while she enjoyed aspects of taking on a darker character, the language barrier proved challenging.

"This language makes German look easy! It's Low German," she groaned. "It's just this small sect of people that speak this type of German that’s harder than German. That was the most difficult part of the job, mainly because they'd given me lines and, you know, somebody had recorded it.

"But then when I got there, they changed the German dialogue. And suddenly I had to work to re-learn these new lines in a language that I don’t understand, and I was just like, aaaa! And the pronunciation! There's somebody who actually does speak the language there, you know, correcting me on like, every little (makes guttural sound). Oh my goodness. So that was the hard part."

Despite her Low German impressing bosses, former How I Met Your Mother star Alyson still isn't convinced she'll pass when it comes to others who speak the language.

"I'm sure that anyone who speaks Low German is going to think that I'm not-at-all good at it," she laughed.