A look at the dialogues of different movie eras
Motion picture was introduced in the country toward the end of the Spanish rule in the 1890s and it was during the American period in 1919 when the first Filipino film, Dalagang Bukid, directed by Jose Nepomuceno,was produced. Adapting film to a local setting was the primary goal of the first generation of directors. Hence, films were based on what entertainment Filipinos were acquainted with—sarsuela (song and dance) and moro-moro (action fantasy). If one has seen our pre-wars films like the melodramatic Tunay na Ina (1939), a scene goes like this:

Rosario Moreno: Tiya, may ipagtatapat kami sa yo (We have a confession to make).
Tiya: Ano yun? (What is it?)
Rosario Moreno (looking at beau): Sabihin mo na (Tell her).
Tiya: Alam ko na ibig n’yong sabihin, na kayo’y… (I know what you mean, you two are…)
Rudy Concepcion: Siya nga po (Yes).
In 1954, Mar S. Torres directed Maalala Mo Kaya?, a love triangle involving a composer, singer, and a bitchy producer. We caught the deep Tagalog exchanges between Rogelio dela Rosa and the young Dolphy on its restored version.
Dolphy: Kay ganda ng umaga para bagang bulaklak ng pag-ibig, ngayon pa lang bumubuka. (It’s a beautiful morning, looks like love is about to blossom just like a flower).
Rogelio: Tama na, puro panunukso yan e. (Stop teasing me).
Dolphy: E talaga naman hindi pa kita nahuhuli ngayon e di nabulok na ang lihim mong pag- ibig kay Pilar. (Really? If I didn’t catch you, your love to Pilar will be unrequited).
Since then the dialogues of our films have been defined and redefined. Danny Zialcita’s Dear Heart (1981) introduced Sharon Cuneta to the Pinoy moviegoers. How did the young generation speak during that time? Here’s an example of Sharon and Gabby Concepcion’s conversation inside the school canteen.

Gabby: Well, if you’re interested daw with somebody, dapat maaga ka, di ba? And you naman, bakit?
Sharon: Babae ako e, dapat konting pakipot, dapat late. ‘Di ba sabi natin, we’ll eat then we’ll talk?
Gabby: Ah, yeah.
Sharon: Eat na.
Today, Tagalog/Filipino and English are our everyday language. Most of us are bilingual, fluent in both languages. Some ideas are better spoken in Tagalog while some thoughts are better said in English.
Once in a while we also get cinematic gems from our regional cinema. Patay na si Hesus (2016), a dark comedy road trip starring Jaclyn Jose uses Cebuano language all throughout the film.
The romantic film One More Chance (2007) continues to mix English and Tagalog in the confrontation scene between John Lloyd Cruz and Bea Alonzo.

John Lloyd: She loved me at my worst. You had me at my best. At binalewala mo lahat yun.
Bea: Popoy, iyon ba ang talaga tingin mo? I just made a choice.
John Lloyd: And you chose to break my heart.
Actors portray roles based on real-life, actual experiences, and conversations. The use of Spanish language in historical films like Peque Gallaga’s Oro Plata Mata (1982) signifies the old rich, snob mestizos. English-speaking characters might mean they are educated and affluent (Take Derek Ramsay in A Secret Affair, 2012). But homegrown Filipinos who speak deep Tagalog are considered “poor” and “hopeless” like Bembol Roco in Lino Brocka’s Maynila sa mga Kuko ng Liwanag (1975). Language in movies distinguishes social classes.

The acceptance of Taglish in local movies especially during the past Metro Manila Film Festivals have brought billion of pesos in overall box office in the theatrical run pre-pandemic times. Even if someone speaks in broken English, mostly in comedy films, the audience readily gets the story.
Once in a while we also get cinematic gems from our regional cinema. Patay na si Hesus (2016), a dark comedy road trip starring Jaclyn Jose uses Cebuano language all throughout the film. It garnered awards from the QCinema International Film Festival 2016 and the Pista ng Pelikulang Pilipino. John Denver Trending (2019) directed by newcomer Arden Rod Condez combines Kinaray-a, Hiligaynon, and Filipino languages. Hailed by the film critics, both delivered powerful messages.
If we want to reach the world market, it is possible that our own language gets adapted to other language. Take Trese on Netflix, the viewer gets to choose if one wants to watch in Tagalog, English, Japanese, etc.
Language is dictated as time passes by. Taglish or not, any language can become universal and can always overcome any language barrier.