When Mayor de Blasio quietly scrapped the requirement for yellow-cab drivers to pass an English test recently, he might have thought he was easing the path to a job for immigrants.

Yet he has no idea the harm he’s done them — and riders, too. Nor do the City Council members who pushed the bill ditching the requirement.

But then, it’s just the latest in the progressives’ thinking that lowering standards, not requiring Americans to speak English and failing to encourage assimilation helps immigrants.

Start with City Councilman Ydanis Rodriguez, who sponsored the legislation. He claimed cabbies didn’t need to know English because in many neighborhoods both the driver and passenger speak the same non-English language.

Rodriguez was once a livery-car driver himself, so it’s perplexing that he doesn’t understand how taxis work.

Fact is, cabbies often pick up passengers in one neighborhood, drop them off in another and then seek riders there. They can’t wait and choose someone who speaks their language; they must take anyone who hails them. If the next fare speaks only English and the driver doesn’t, let’s be honest: It’s a problem.

Our mayor is equally clueless. On the Brian Lehrer show last week, a caller asked him to explain the bill’s rationale. De Blasio said, “The reality is that in a time in which people have all sorts of electronic devices to help them get around” drivers don’t need much English.

Reality? As Lehrer noted, yellow and green cabs in New York are specifically prohibited from using even hands-free devices such as GPS while driving.

Besides, road signs are in English and emergency information is relayed in English. And most of the people cabbies interact with daily — even aside from passengers — speak English.

Supporters of the bill pointed out that Uber drivers don’t have to take an English test. But Uber has different rules than the yellow cabs. Uber drivers are allowed to use GPS, for example. And if the driver is unable to communicate with his riders and this affects the trip, riders can penalize him through Uber’s rating system.

By contrast, if a yellow-cab driver gets lost because he can’t use GPS and has poor command of English, many disgruntled passengers will never bother to alert anyone about it. So the mayor and City Council are inviting incompetence — and with no repercussions.

But the real issue here goes well beyond cab drivers. Too many progressives want to dismiss the notion that learning English is important to live and work in America. We keep sending the message to immigrants that learning English is optional. After all, as Councilman Rodriguez says, they can just stay in their own neighborhoods.

It’s not the first time de Blasio has failed to understand the importance of language. As public advocate, he opposed an NYPD rule that cops speak only English when on duty. “It’s wrongheaded and indefensible, and it has to stop this instant,” he said at the time.

No one is saying a taxi driver should have perfect English before getting behind the wheel. My own father drove for a car service when we arrived here from the Soviet Union in the late 1970s. On his front seat, he kept a dictionary to look up any words his passengers might use that he didn’t know.

But his lack of English was a gigantic minus, leaving him stuck driving a cab in Russian-speaking areas only until it improved.

Learning our country’s most-used language is clearly important for drivers who hope to move on to other careers. A 2013 study by Purdue economists Brigitte Waldorf and Raymond Florax found that immigrants who segregate themselves into the kind of enclaves Rodriguez and de Blasio encourage and don’t learn English “limit their occupational opportunities.”

It also seems obvious that speaking America’s primary language is important off the job, too — whether dealing with cashiers, teachers, public officials or just neighbors. Yet, our “progressive” political leaders pooh-pooh the idea, drop requirements to learn the language and make accommodations to “enable” non-English speakers to “get by” speaking their native tongue.

Government notices are translated into numerous foreign languages. Our public schools fail to adequately transition foreign-speaking students to English. What an enormous disservice we do them.

It’s long past time to stop thinking we’re doing immigrants a favor by discouraging them from assimilating into American culture and from looking to “get by” without knowing the language. Our zeal to be as accommodating as possible only holds them back from reaching their full potential. And they’re the ones who pay the price.