The 33-year-old has been learning the language so she can take part in a singing event at this year’s Royal National Mod.
McManus will be singing in the Silver Pendant, which is seen as the most prestigious singing competition for Gaelic learners at the Mod.
The singer and television presenter, who won the 2003 series of Pop Idol, will be taking part in the event which is organised annually by An Comun Gaidhealach, and being held in Paisley later this month.
McManus said agreeing to take part in the competition brought back all her Pop Idol nerves. However, she added that she might release an album in Gaelic next year if her singing was well received.
She said: “Learning Gaelic has been a really hobby for me. I have totally immersed myself in it.
“Earlier this year I was asked if I wanted to take part in the singing competition at the Mod.
“Singing in another language is a real challenge. It is different from something like Pop Idol, but all the nerves have returned now I’m in another singing competition.”
She added: “I sometimes wonder why I’m putting myself through it all again.
“It is single-handedly the hardest thing I have ever done.
“I’m thinking of making some more music next year and maybe the next album I make will be in Gaelic. If I don’t get booed off the stage at the Mod I might.”
To prepare for her competitive debut at the Mod, McManus has been required to pass a Gaelic test, which she did earlier this week.
Speaking about her exams, she said: “I very nervously made another attempt to pass my Gaelic speaking Silver Card and I’m completely relieved to reveal I did it.
“It was second time lucky for me to achieve the required pass mark, which took months of effort and studying.
“It now means I can go ahead with my plans to compete in this year’s Silver Pendant category this month.”
The event and McManus’ singing competition will be broadcast later this year on BBC Alba.
John Morrison, chief executive of An Comunn Gàidhealach, said : “We’re delighted to welcome Michelle as a competitor at this year’s Royal National Mod. It’s always daunting for new Gaelic speakers to compete to such a prestigious audience, however we think Michelle will do well and we wish her the very best of luck in the Silver Pendant.