On various social media outlets, I frequently get comments of this type:

This is CI for [Spanish/French]. We share about comprehension-based techniques and methods that work in our [Spanish/French] classes. It doesn’t matter whether these things work with zero-language students or for students who are learning [language other than Spanish/French]. 

And that’s lovely. As long as you’re not at all concerned that anyone reading that is teaching anything other than Spanish or French.

Some teachers teach multiple languages. And many teachers of non-Spanish/French read groups “intended for” teachers of Spanish/French because there is far more TCI-oriented information available out there for teachers of Spanish/French. Those teachers read about techniques that can work with Spanish/French because of the overlap with English, and they do not see anyone saying “yes, this works because Spanish/French but just keep in mind…”, so they try it with their languages. And it fails. And then they conclude that it’s Comprehensible Input that failed, because they did it exactly how they said to do it in that online group.

You can “get away” with stuff in Spanish and French that you can’t even think about doing in languages that don’t have the cognates and the alphabet or both. You can go to a catalog and order TCI-friendly readers in Spanish and French. You cannot do that in many other languages. You can get suggestions from experienced colleagues in Spanish and French — but for many other languages, all the teachers pretty much start at the same time and have little experience, so they must rely on hints from people who teach, well, Spanish and French.

The other compelling argument for being just a little bit more careful about making claims for techniques is our students. Most of the stuff that you can get away with in Spanish and French is possible because the students are assumed to be fluent native speakers of English. If you remove that prop, you now have something more like the establishing-meaning imperative that faces teachers of Other Languages all the time. You can’t lean on the cognates when the student’s native language doesn’t share them with your target language.

It’s fine to use the advantages your particular teaching language has with regards to the population of students you’re teaching. But it’s also very good to remember that on the internet, the people who are commenting are only the tip of the tip of the iceberg. There are so many more who only read quietly and never ask questions. I think it’s the responsible thing to take a quick mental step back and think about whether something you’re proposing is language- or situation-specific and SAY SO if it is. It’s good for the lurkers, and it’s also good for posters in that it forces a bit of introspection and a look at their practice from the perspective of LANGUAGE acquisition, not SPANISH/FRENCH acquisition by English speakers.