In the program Factor Fobia, Marley uses two words that are very similar sounding, atrás and tras.
Tuve un... hace unos meses atrás, me he ido a China.
I had a... some months ago, I've been to China.
Captions 28-29, Factor Fobia - Cucarachas
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As is evident, atrás can be used to indicate "ago," as in time past.
Yo empecé hace tres años atrás en el grupo Guamanique,
I started three years ago in the Guamanique group,
se llama Ballet Folklórico Guamanique, que es de Puerto Rico.
it's called the Guamanique Folk Ballet, which is from Puerto Rico.
Captions 3-4, Baile Folklórico de Puerto Rico - Los Bailarines
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Muchos años atrás, él fue general.
Many years ago, he was a general.
La última vez que nos vimos habrá sido unos seis años atrás.
Last time we met may have been some six years ago.
Of course, atrás is also commonly used to indicate "backwards" or "towards the back."
Si eso era un primer paso, había sido un paso atrás.
If that was a first move, it had been a move backwards.
Caption 24, Los Años Maravillosos - Capítulo 2
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Ella fue atrás.
She went backwards.
Vaya hacia atrás, por favor.
Go backwards, please.