One parent, one language with three languages

The sources read for this site do not test one parent, one language (OPOL) with three languages, so no honest answer can say it works or fails there. What King and Mackey say in The Bilingual Edge is about two languages: OPOL is popular and often works, and some children raised in it become passive bilinguals. This page sets out that evidence, then gives practical advice for three languages, labeled as advice.

What the sources say about two languages

In ch. 6, King and Mackey note that many children reared in one-parent, one-language families become passive bilinguals rather than active ones: they understand both languages well but speak only one proficiently. Their case is Sarah, whose German-speaking father and English-speaking mother raised her in two languages. She understood German but insisted on speaking English.

They reason that two languages are never on exactly equal footing outside the home. So they suggest that parents in mixed families consider extra support for the weaker, minority language inside the home, and they give 80 percent of child interaction in that language and 20 percent in the majority language as a goal one might set. Both points are written for two languages.

What the sources say about three

Ch. 11 covers three or more languages. The authors' position is that it is not significantly riskier or harder than one or two, but that it needs more deliberate balancing: without roughly equal quantity and quality of input, a child tends to become a passive user of the language that gets the least real time.

They also mention, as one approach some families use, fairly firm language rules at home, each parent sticking to one language with the child, and leaving a third language, often the community language, to school, playgroups or the neighborhood. They present it as one possibility among several. That is OPOL extended to a third language, and the sources we read describe it. They do not test it, and they give no figures on how well it works.

Practical ways to assign three languages

This section is practical advice. Nothing read for this site tests it, and it promises no outcome. Pick the case closest to yours.

• Two parents, two languages, and the school speaks the third. The simplest assignment is one language per parent, with the school language arriving through school. This is the shape the ch. 11 approach describes. The home then has two languages to balance with each other, and the school language to balance against.
• Two parents, and one of them speaks two of the languages. Decide in advance which language that parent uses with the child, and keep to it long enough to see how it goes. Switching by mood makes it hard to tell what the child actually hears.
• Two parents, and a third adult language held by someone else. A grandparent, a relative on video calls or a babysitter can carry it. One reported example in ch. 11 is Livia, raised with four languages, who used three by age eight after she stopped interacting with her Urdu-speaking babysitter. Name who carries each language, and what happens when that person is away.

In every case, write down the assignment. A plain list of who speaks which language with the child, and when, is easier to check against a real week than an intention.

Checking the assignment against a real week

The Family Language Audit takes each caregiver's weekly hours and the language they use with the child. Once a language has been added to the child, the page stops giving the two-language 80% verdict and shows each language's hours and share of waking hours against an even split, and flags a language under half of its fair share. The half-share cutoff is a proxy the app chose, not a research threshold.

ILLUSTRATION with invented hours, run through the audit code: a 4-year-old, Spanish from the mother, Portuguese from the father, English from school and the neighborhood. The app's waking-hours figure for ages 3 to 5 is 80.5 a week, a working estimate with no cited source (UNVERIFIED). The mother logs 14 hours, the father 12 and school 30. The shares are 17 %, 15 % and 37 %. An even split is 33 %, and half of it is 16.7 %, so Portuguese is flagged and Spanish sits just above the line. The line is the app's own, and this week shows how close two parents can be to it while each has the same one-language rule.

One more point about the same page. With a third language added, the headline says the 80 percent line is King and Mackey's figure for two languages and gives their even-share rule of thumb instead. The two-language bar and the OPOL note are not shown, and hours logged under the added language count in the per-language section. The 80 percent goal was written for two languages, and the sources read do not extend it to three, so for three languages read the per-language section.

What is still unknown

• Whether one parent, one language works as well, worse or differently with three languages. No source read for this site tests it.
• How to split a child's time between two home languages when both are minority languages. The 80/20 idea in ch. 6 is about one weaker language against the majority language.
• Whether leaving the third language to school gives it enough input. The authors describe the approach as one possibility, not a tested method.