Spelling and correction languages on MacBook Air (M1, 2020)

Hi,

I have some problems with spelling and autocorrecting in MS Office, for example, Word. When I write incorrect word in latvian, the OS doesn't underline it and it shows like correct, forthemore, I have this error like on the picture.

After this, I try to use Pages, and I wrote this word incorrect and OS underlined it! And I can write it correct. But, there are one more error like this: on my macbook I use Latvian and Russian languages, but in Pages I wrote in Latvian and it was underlined, and I can correct it, but when I press the "Enter" x2, I wrote word in Russian, but it was underlined like a mistake (but it was correct).

I understood that my MacBook cannot automatically change language while I am writting. What I should do?