A native of the southern, mainly Russian-speaking city of Kherson, she now has about 110,000 people following her on Instagram, where she posts short videos with tips on building Ukrainian vocabulary and improving speaking skills.

Business is booming. She has launched an online training course on public speaking in Ukrainian. Individual coaching sessions are booked up for months and she is looking for more space for lessons at her theatre studio in central Kyiv.

"I am learning Ukrainian together with people. I have found my own approach and try to do it in an easy, entertaining and friendly manner," said Belozorenko, 35.

For big companies, a switch to Ukrainian has been swift since last year's invasion after decades in which Russian was the main language of commerce.

Data from job search platform Work.ua showed employers posted 84% of vacancies in Ukrainian and 13% in Russian at the end of 2022. In 2015 it was nearly the opposite: 16% of vacancies were in Ukrainian and 80% in Russian.

Businesses in once Russian-speaking cities of Odesa, Dnipro and Kharkiv were switching to Ukrainian the fastest, it said.

Ukraine's biggest banks have removed Russian from their mobile applications and websites. Monobank, with 7 million retail clients, updated its app in September 2022 to Ukrainian only. By that point, usage of its Russian-language version had already declined by 30% since the full-scale invasion.

DIFFICULT PROCESS

Ukrainian is the country's official language, but most Ukrainians are bilingual after generations of Soviet and imperial rule when Russian language was promoted and Ukrainian culture repressed.

Ukrainian has traditionally been more widely spoken in the west, while Russian was more prevalent in the south and east, as well as the streets of the capital Kyiv.

Many Ukrainians across the country are seeking to erase Russia's influence, to reinforce their independence from a neighbour whose invading troops have destroyed Ukrainian cities and killed thousands.

The most prominent switcher is President Volodymyr Zelenskiy, from the predominantly Russian-speaking southern city of Kryvyi Rih, who initially gained fame as a comic performing in Russian but now almost never speaks it in public.

A process of "de-Russification", begun after 2014 when Moscow seized and annexed the Crimea peninsula and backed proxy forces waging war in the east, has rapidly accelerated since Russia's full-blown invasion last year.

Streets, towns and villages have been renamed - including 288 streets in Kyiv alone - and statues of Russian historical figures pulled down. State railway Ukrzalizhnytsia has launched a three-year programme to rename stations and change signs "to destroy everything which connects us with the aggressor country".

Moscow argues that policies to encourage Ukrainian amount to discrimination against Russian speakers, one of its claimed justifications for invading.

Kyiv denies it involves coercion, and says it reflects a nationwide popular yearning. But there are signs that some people are finding the transition difficult.

Official education is now meant to be conducted only in Ukrainian and Russian is banned on the campus of one of the country's leading liberal universities, Kyiv Mohyla Academy.

This month, Liubov Vorobyova, a lecturer from Irpin State Tax University north of Kyiv, declined a student request to switch into Ukrainian during an online philosophy class, saying it was hard to adjust after teaching for 35 years in Russian.

A video from the class was posted on social media, causing an uproar. The university said the lecturer was suspended and an investigation into the matter was ongoing. Reuters was unable to reach Vorobyova for comment.

Belozorenko says her classes to teach people to be more comfortable using Ukrainian in public aim to "support but not criticize". She takes greatest pride in a change she says took place without her prodding.

Her Russian-speaking parents lived under Russian occupation for months in Kherson region before a Ukrainian counter-offensive recaptured the area last year.

"In our family chat with my parents and my brother, we started using Ukrainian and it happened without my interference," Belozorenko said.

(Reporting by Olena Harmash; Editing by Mike Collett-White and Peter Graff)

By Olena Harmash