This method of learning languages seems to be called Bilingual-Dichotic Method. (Dichotic: involving or relating to the simultaneous stimulation of the right and left ear by different sounds.)
Here are two relevant links. The first is to a scientific study: Bilingual-Dichotic Learning of Foreign-Language Vocabulary: Visual Cued-Recall and Phrases.
One metric for how similar languages are to each other is based on the concept of Linguistic Distance. Unlike some approximations that are more subjective (ie. This languages sounds a lot like that language), linguistic distance is quantifiable. This is important because it gives a concrete comparison of two languages.
Using a statistical approach (called ...
Translanguaging is defined as:
“the ability of multilingual speakers to shuttle between
languages, treating the diverse languages that form their
repertoire as an integrated system”
In a sense, it's a system that leans towards treating your language abilities as not extensions of your L1, but as an integrated system that all works ...
H. H. Stern in Fundamental Concepts of Language Teaching traces the L1/L2 distinction back to the 1959 article, The teaching of English as a foreign language by J.C. Catford:
The ‘L1’/‘L2’ distinction was introduced by Catford in 1959. ‘One
may, for convenience, use the abbreviation “L1” for primary
language, and “L2” for secondary language. L1 is ...
This reminded me of several things:
Paraphasia can lead to word substitutions, but seems to affect speech rather than reading. See also semantic paraphasia in Psychology Dictionary.
A "lexical selection error" and "substitution" (listed in Speech error on Wikipedia) also appear to refer (primarily?) to speech.
Semantic dyslexia: 'Those who suffer from ...
I take it that medium of instruction includes the language of instruction. And that language of instructions is the language in which the target language is being taught.
(Unfortunately, I don't have a source for this but that's my sense from the literature I've read while researching and writing about language teaching)
The situation you are describing is called diglossia. Language A is the vernacular. The term may refer to a dialect as opposed to the literary or public forms of the same language ("African-American vernacular English"), as well as to a national language as opposed to a lingua franca (such as Latin in the medieval times).
All credit to Mitch for this answer, but a very similar question was posted to Linguistics.SE:
There are qualitative and quantitative measures for 'distance'.
Qualitatively, many languages are easier to compare simply by know
something about their family tree, which is implicitly recognizable
(if one is lucky enough to know so many languages so ...
I'm afraid there's no commonly accepted term for that.
Many schools use the following construct:
L2 for L1 speakers
For example (mind the URLs and titles as well):
Everyday Chinese for German Speakers
English for Russian Speakers
So, in your case it would be Russian for English speakers, regardless the fact that the student's L1 is Khmer.
Scott Thornbury has an interesting entry about different ways the term fluency has been understood:
[...] fluency is one of those elusive, fuzzy, even contested, terms that means different things to different people. In lay terms, a “fluent speaker of French” is probably someone whose French is judged as accurate, easy on the ear, and idiomatic. The term, ...
I tend to say "doesn't translate well", however a term that fits the bill is Realia:
In translation, Realia (plural noun) are words and expressions for culture-specific material elements.
Realia must not be confused with terminology: the latter is primarily used in the scientific literature to designate things that pertain to the scientific sphere, ...
If this is about what goes on in your mind instead of what's in the dictionary, the usual linguistic term is word finding difficulty.
Word finding difficulties are usually studied in the context of language attrition, which also includes first language attrition or FLA. In this context, you can also come across the term lexical first language attrition. (...
Frankly, I think a lot of this is embedded in the term "prestige language" as it is.
Being learned later is usual for prestige languages, since they're are usually taught in school and not used at home,
In fact, it took me a second to work around your question because "prestige language" equates to "more or less native" in my head. There will be people ...
You can "learn" a language like Spanish in the sense of memorizing lists of vocabulary and conjugation charts. To some extent, it also means learning academic content words and sentence structures. You cannot necessarily hold a conversation or understand it beyond the textbook, though. On the other hand, many native speakers never "learn" their own language ...
Mutual Intelligibility is a relationship between languages or dialects in which speakers of different but related varieties can readily understand each other without prior familiarity or special effort.
Is there a list of mutually intelligible languages?
How can mutual intelligibility be measured?
Linguistics.SE questions tagged mutual-...
There seem to be two questions here.
The name 'communicative language teaching'
Names of things have a history, and they do not always accurately describe the thing named. Communicative language teaching, according to the Wikipedia page, has a greater focus on communication as a goal and a method of teaching than some other methods.
How is it different