Over the last few days, I revisited my prior observation that a minimum of 50% exposure to CLE (Chinese language ecosystem) before age of 8 is required to reach ILR level 3 or above in terms of speaking proficiency.  Having seen how a few of the younger fellow parents’ children have blossomed in terms of their Chinese proficiency over the last two years since I started my FB group Raising Bilingual Children in Chinese and English and joined 中英文雙語並進的養兒育女手記 another similar group composed mainly of adult immigrant parents, I reached out to some of them and made revision and refinement to my observation and expanded it to specifically reading proficiency.

Now, there are very few parent members of my FB group having pre-college children with ILR level 3 or above in terms of reading proficiency above the age of 9 or so, except for my daughters and maybe a couple of other children.  The main reason, I believe, is as follows:

1. Few success stories.  There are few heritage parents who were as “aggressive” in pursuing reading proficiency for their preschoolers around 6-10 years ago – so there are few “success” stories to share by their tween/teens.
2. Selection bias.  Most heritage children older than 8-9 learning Chinese have speaking, reading, or both IRL proficiency level lower than 3, and most those parents are resigned to the “reality” that their children will not achieve ILR level 3 or above in the foreseeable future, without spending extended time in the “motherland”.  So, these parents don’t seek out and join FB groups such as the two mentioned.
3. Social media usage bias.  There are likely fewer older heritage parents who use FB or other social media.   Also, adult immigrant parents from mainland China may use WeChat or other social media sites more, seeing that Facebook is not accessible in China.   So, that is another selection bias.

My observation shifts as I gather feedback from other parents and their children.  So, please give me some feedback!

In any case, with these biases in mind, my current observation is as follow:

I)  Speaking proficiency.  It takes a minimum of ~66% exposure to CLE from at least 3 to 8 years old to achieve and maintain speaking proficiency of ILR level 3 and above between those ages.  That would be about 2/3 of the waking hours immersed in CLE.  The higher the percentage, the higher the IRL level.  Having said that, a children immersed in ~ 66% CLE time probably can achieve ILR level 3-3.5 by 8.  This does not necessarily extend to higher age groups, at which time language complexity and range of expression is increased.  To maintain or increase age-matched ILR level would require additional instruction and/or exposure to active/passive usage of more advanced vocabulary and expression, such as spending extended time with pretty much native level speakers or consuming multimedia programs (video/audio).  In addition, active learning/instruction likely decrease the CLE % time requirement.

A child can be doing an English based assignment at home but communicates to the parents or care giver in Chinese.  I would include that time as part of CLE also.  However, watching English TV programs at home likely would not count.  On the other hand, watching Chinese TV programs at an English speaking household would count as part of CLE.  The main determinant would be whether the child is actively using or learning Chinese.

1. Chinese immersion schools count as 50% CLE for those hours at best, as the children plays in English and active use of Chinese is mostly done by the teacher, according to my understanding.  Past second grade, this percentage likely decreases as more English is used and added to the curriculum.
2. Half day preschool counts as 1/3 of the waking hours.  Full day school counts as 1/2 of the waking hours.  Don’t forget to include the weekend, holidays, and winter/summer break.  Generally speaking, there are 180 days of school instructions.
3. With the above understanding, for non-Chinese speaking families, full day Chinese immersion school since kindergarten only counts as no more than 15-20% CLE time (50% CLE efficiency x 50% of each day x 50% of the year) without additional enrichment, with some homework/studying time added in.  That’s why immersion school by itself is insufficient to achieve proficiency level of ILR level 3 or above.
4. Heritage children at Chinese speaking household who attend English only schools likely have “maximum” 75% CLE time, but likely frequently get much less, if they consume mostly English based multimedia and play with other children in English.  Their proficiency frequently go dramatically downwards past 6-7 years of age as the slower pace of Chinese language instruction they receive at weekend Chinese school is not enough to maintain age-matched IRL level 3.  These children mostly speak English or a mix of English and Chinese (“Chinglish”) to their parents, who speak Chinese to them.
5. Heritage children attending Chinese immersion school with Chinese speaking household can have up to ~80% CLE time, if Chinese is strictly used outside of school.  However, the slower pace of Chinese instruction at immersion school to accommodate non-heritage children will likely decrease their age-matched IRL level over time. Extracurricular activities conducted in English can put a big dent on CLE time but that is the case for any children.
6. My daughters who have had spent half of their days in English only day care, home day care, preschools, kindergarten and up since birth pretty much (except for ~ one year and half when we homeschooled) plus sojourns abroad in Taiwan with 100% CLE, probably have CLE time of ~ 70%.  They receive Chinese instruction at home using Chinese language art curriculum from Taiwan at relatively fast pace in terms of reading (~1/2 to 2/3 of the pace in Taiwan, foregoing most of the writing practices) and consume Chinese multimedia in “concentrated” form (and thus less time consuming), as I gathered for them multimedia that highlight the intricacies and salient features of the languages in its various forms.
7. Heritage children who are homeschooled in Chinese in Chinese speaking household likely can achieve CLE exposure time north of 80%.
8. Multi-ethnic children with one Chinese speaking parent who are homeschooled in Chinese but exposed to parents communicating in English and who communicates to one parent in English and the other in Chinese probably have CLE exposure of ~ 60-70%.
9. Multi-ethnic children who attend Chinese immersion school with one non-Chinese speaking parent may achieve ~40-70%, depending on the amount of Chinese used at home and extra Chinese language based enrichment, including playdates.

With the above in mind, it seems general English speaking proficiency of ILR level 4-4.5 “only” requires ~ 20-30% exposure time.  If one lowers the standard to ILR level 3-3.5, exposure time of ~15-20% will likely suffice for English.

The above brings to mind that bilingual proficiency in English plus another category 1 language in a household where both of those languages (say, English-Spanish or English-French) are used is relatively easy, compared to English-Chinese bilingualism.

As for trilingual families, a child attending English speaking schools in English-French-Chinese household where the parents speak in English and one parents speak to the children in Chinese and the other in French can achieve ILR level 5 (native) in English and French, at the expense of Chinese proficiency, since CLE exposure time would likely be less than 50%, which would tend to decrease further as child grows older.  On the other hand, a Chinese heritage child with Chinese speaking parents attending English-Spanish immersion school may have up to 70% CLE time if Chinese is strictly used at home.  However, further maintenance of Chinese ILR age-matched level past ~ 8 can depend on Chinese language instructions.  Similarly, a trilingual-biracial family (say, Polish-English-Chinese) in Taiwan who homeschools in the three languages may achieve CLE time of ~70%, which may indeed be sufficient for trilingual proficiency at or above 4 in all three languages over time.

My observation that it takes ~ 66% language ecosystem exposure time to achieve Chinese ILR level ~3 speaking proficiency vs.~15-20% exposure time for English (or French, Spanish likely) to achieve similar IRL level, or a ~4 fold difference, would be in line with what the Foreign Service Institutes of the US Department of States suggested (~ 4 times as long) for English speaking adults to learn Chinese to ILR level 3 vs. a category 1 language.

(to be continued……)