Keira Knightley thinks it's a ''miracle'' she's still married after her husband tried to teach her to play guitar.

The 'Begin Again' star - who plays aspiring singer Greta in the upcoming comedy-drama - admits she almost fell out with her beau James Righton because he got frustrated with her lack of ''ability'' to play the instrument.

Speaking on the 'Today' show yesterday (27.06.14), Keira - who plays guitar in the movie - said: ''He is a musician and he did try [to teach me guitar]. It didn't go so well, it's a miracle we're still married. I didn't have the natural ability for the guitar. It was a little bit stressful but we're still together, so it was fine, and I didn't kill him and he didn't kill me, so it was fine.''

Meanwhile, the 29-year-old actress admits she's regularly mistaken for her fellow celebrities Britney Spears, Kate Winslet, Rachel Weisz, and Natalie Portman, but tries to see it as an advantage.

She explained: ''Three times [I've been mistaken for] Britney, mostly Natalie Portman, and I've also had Kate Winslet, I've also had Rachel Weisz. I always sign for other people. [I sign] their names.

''I've been Natalie a million times. I've been chased through airports as Natalie Portman.''