Some children learn their first words before they crawl, while others start speaking long after they've learned to run.

As a parent, natural variability in language acquisition can be anxiety-inducing — even though passing on language to children is seemingly the most natural thing in the world.

But when it comes to raising a child bilingually, passing on languages other than English doesn't necessary feel 'natural' in Australia because of the way our society centres English.

Yet linguistic diversity is a fundamental aspect of who we are, and millions of us speak languages other than English.

The home language

From the moment I fell pregnant, my chief worry was whether I would be able to pass on Vietnamese to my child.

It's technically my first language — but my fluency is far from perfect, as I've been dominant in English since starting school.

This is common scenario for parents born and raised here, as well as those who weren't born here but have spent their most formative years in Australia.

For Zarlasht Sawari, the issue of bilingual parenting is also a pressing one.

Born and raised in Perth, she grew up speaking Dari, a variation of Farsi.

Zarlasht has grown to appreciate her mum's insistence on her learning Dari. ( Supplied: Jacquie Manning )

Zarlasht has two children: a newborn and a seven-year-old.

"It was a really important thing for my parents, for my family, that we all speak our language at home," she says.

"So as soon as we walk in the door, stop speaking English, speak Dari. My mum really was strict on us and I really appreciate it so much now."

Like Zarlasht, when I was growing up there wasn't necessarily a choice when it came to speaking Vietnamese.

But even so, during my youth I already had a sense our language was slipping.

I recall telling my younger brother we should try to speak to each other in Vietnamese rather than English, our preferred language. (It didn't work.)

'It is a full-time job'

One couple who have successfully created a bilingual environment at home are Triin Pehk and Rob Morris.

Triin and Rob want their daughters to learn Estonian as well as English. ( Supplied )

Triin migrated from Estonia as an adult and over the years has invested a huge amount of effort and energy into passing on Estonian to her two daughters.

She has taken quite a strict approach — but now they're both able to speak Estonian, despite the odds.

"It is one of the hardest things I've ever done, it is a full-time job," Triin says.

"I have to artificially do a lot of work; every day, every second.

"I have a friend who's a linguist and we've talked about every theory, we've read the research. And the best way is: one parent, one language."

At some point during our discussion, Triin turned the tables and posed the following question to me: "Why is it so important for the second generation immigrant to pass on the language?"

It was a confronting question I didn't have a ready answer for.

The best answer I could give, which is still my answer now, is that passing on language is important to me because I believe in multilingualism.

There are also benefits such as a more agile brain and access to other cultures and communities.

The gift of language

Languages enrich our perceptions and understandings of the world. You miss out on so much if you never learn another language.

It's why I've invested a lot of time into learning other languages over the years, in addition to improving both my English and Vietnamese.

Dylan is taking time to teach his son Welsh. ( Supplied )

Hanna Torsh is a linguist and author of Linguistic Intermarriage in Australia, focusing on mixed language couples.

In her research, she found it was mothers who are the ones primarily occupied with raising children in languages other than English in Australia, including mothers who have an English-speaking background.

"The English-speaking background mothers in my study not only took on the responsibility for bilingual child rearing, they also felt responsible for communicating with their in-laws," she says.

"I think that's because of the social expectations that we have about women and their role in maintaining social relationships, what I call 'kinwork'."

Of course, fathers also undertake the work of passing on language to their children.

Dylan Wynne, whose first language is Welsh, is taking the lead in his family in passing on language. His wife has an English-speaking background.

"They say that you need 20 hours of one-to-one per week in the form of immersion; that's quite challenging for someone that works full-time," he says.

"So it's good when I get my afternoons off to go to the Welsh playgroup on Sundays.

"When my son was first born, there was no doubt that I would speak Welsh from the very beginning.

"And I think if anything's coming from the heart, it's what comes automatically. It's the most beautiful thing."

Discussing the problem of raising a child bilingually with so many parents has been reassuring, and motivated me to persevere even though it's hard work.

Bestowing my daughter with an additional language will be a great gift; it will give her a more coherent sense of identity, particularly as she is someone who will grow up mixed-race in Australia.