Today, English. Tomorrow, Spanish.

The sound of a galloping rhino thunders on the busy Parisian street.

``It ran over my cat, it ran over my cat!" the Housewife wails. ``My cat, my poor little cat . . ."

Later that night, the Housewife, played by Mari Davila , becomes ``La Señora."

Cue the pounding rhinoceros and the crying housewife.

``Ha aplastado a mi gato! Ha aplastado a mi gato!" she bawls in Spanish during a rehearsal. ``Mi pobre Misu, mi pobre Misu!"

The scene is from Eugene Ionesco's ``Rhinoceros," or ``Rinoceronte ," which Chelsea's TheatreZone is presenting in English and Spanish along the Chelsea waterfront starting Wednesday.

Davila plays the same role in both languages. And in doing so, she's part of a sustained effort to make theater more accessible for Spanish-language audiences in Chelsea and Greater Boston.

The outdoor performances (one language per night) mark the fourth year the company has staged a play in two languages, using an ensemble of mostly local bilingual actors. Because of a shortage of truly fluent Spanish-speaking actors in Greater Boston, many of the actors do double duty to fill out the cast.

And the actors don't seem to mind the extra lines. For some whose first language is Spanish, the bilingual productions let them entertain fellow Hispanic audiences who might not be interested in English-language-only plays.

``I feel proud that I could use my native tongue," says Karla Trigueros , a Salvadoran-born actress who heard about TheatreZone's casting call this spring and auditioned in English. When artistic director Danielle Fauteux Jacques learned that Trigueros was just as fluent in Spanish, she asked her to play the role of Mrs. Boeuf in English and El Tendero (the Grocer) in Spanish.

Does it get confusing playing different characters, of different genders, in different languages?

``Not at all," says Trigueros, 26, who lives in Malden. ``They are very clearly defined individuals, and they are in different parts of the play. Besides, I can switch like that from English to Spanish," she says, snapping her fingers. ``Now my family can see me [in a play] without falling asleep because they'll understand what I'm saying."

Davila, who plays the Housewife in both casts, says her portrayal is influenced by the natural inflections of the different languages. In a rehearsal at TheatreZone's production space, she seemed more animated in the Spanish version.

``I am sure the inflection is different in an unconscious way," says Davila, whose first language is Spanish. ``The lines are very similar. They are almost a literal translation between Spanish and English."

Other local productions, such as the 2004 debut of ``Sonia Flew" by the Huntington Theatre Company , have included Spanish dialogue. Local community theater groups such as Escena Latina in Jamaica Plain have also done productions solely in Spanish.

But in having a bilingual focus, TheatreZone joins at least a handful of troupes nationally that perform concurrently in both languages. Other companies include the Bilingual Foundation of the Arts in Los Angeles and the Puerto Rican Traveling Theatre in New York. Repertorio Español, another New York company, produces plays in Spanish, but non-Spanish-speakers can follow along by wearing a wireless headset that simulcasts the lines in English.

Fauteux Jacques began adding a Spanish version of her company's outdoor summer productions in 2003 to appeal to audiences in Chelsea, a largely immigrant community where Spanish often peppers street conversations.

``Chelsea is really a bilingual community, 50-50 English and Spanish," says Fauteux Jacques, a bilingual Massachusetts native. She learned Spanish from visiting friends in Puerto Rico and used to teach Spanish at Emerson College and Tufts University.

``We are trying to be a professional theater that is responsive to the community. Spanish speakers aren't going to think of coming to a show that's not in their language. It's more accessible to do a show in their language," she says.

So far, the response to the bilingual performances has been strong. Last year, an average of 100 people sat each night on the lawns of Chelsea's Mary O'Malley Park to watch the play in one language or another, Fauteux Jacques says. Sometimes people come twice, she says, to see how the actors change their performance when switching languages.

Last summer's production of Anton Chekhov's ``The Seagull," or ``La Gaviota," brought out such large crowds that Fauteux Jacques decided to expand the run from two to three weeks this year.

Ionesco's absurdist comedy focuses on a group of townspeople who spot one rhino after another running loose in the street. The play looks at society's herd mentality and questions whether there are any truly independent thinkers in the world. The main character, Berenger , watches as, one by one, friends, coworkers, and townsfolk turn into rhinos.

Fauteux Jacques looked for 30 actors to play 17 speaking roles but came up short in the Spanish-language acting pool.

Unlike major Latino cities such as Miami or Los Angeles, which are booming Latino entertainment markets for Spanish-speaking actors, Boston, with a population that's 16 percent Hispanic, has a dearth of talent, Fauteux Jacques says.

``The Spanish-speaking talent pool in Boston is smaller than you'd expect," she says. ``When you think of what a large Spanish-speaking community we have, there are really not that many actors."

Some Spanish-speaking actors at a recent rehearsal in Chelsea speculated that one reason might be that many Hispanics here are hard-working immigrants who may not have the time to commit to a play, while others may be young people focusing on their college studies.

So Fauteux Jacques sends out flurries of e-mails and press releases to Spanish-language media to get the word out for her casting calls. Or she dives into her 2-inch file of head shots of Spanish-speaking actors from recent years to see if they'll come out for an audition. Sometimes she learns that they have moved away to bigger cities to find more stable work. For her Spanish-language casting call, only 20 people showed up, she says. Some were turned away because either their acting or their Spanish skills weren't up to par.

Davila, 44, who studied acting in college and performed in last summer's ``La Gaviota," returned this spring to audition so she could act in her native language.

``It's very rewarding to do a play in Spanish," says the Puerto Rican-born software engineer who lives in Stow. ``I don't speak Spanish usually. I have kids, and they speak English. I find doing a play in Spanish a lot of fun. It feels like home, like I am talking to someone in Puerto Rico. It's rewarding."

Davila describes her character -- the Housewife who cries after losing her cat to a rhino hit-and-run -- as a ``Paris Hilton type in her 40s." During a recent rehearsal, she held the script in one hand and a stuffed teddy bear -- a sub for the dead cat -- for the English rehearsal. Then later that night, she switched scripts to rehearse the same scene in Spanish.

Despite rehearsals that end at 10 p.m. and the one-hour drive each way from Chelsea to Stow , Davila says, ``It's worth it."

``This is the only place I can act in Spanish," she says during a rehearsal break, before returning to her dual role.

Johnny Diaz can be reached at jodiaz@globe.com.