Rose Byrne may be a fine actress, but her ability to spell leaves a lot to be desired. On the 'Late Show' last night, Byrne competed against David Letterman in an impromptu spelling bee and failed miserably.

First, Letterman correctly spelled "Schenectady," the city in New York State where Byrne is currently filming a movie with Bradley Cooper, Ryan Gosling and Eva Mendes.

Not to be outdone, Byrne then attempted to spell "Indianapolis." After a promising start, she actually managed to spell two-thirds of the word correctly. But eventually she lost her way and began shouting out random vowels despite Letterman's help.

[Late Show With David Letterman]