In which word should the letter "ya" be written instead of the gap - dog? - briefly
The letter "я" should replace the gap in the word "собака".
In which word should the letter "ya" be written instead of the gap - dog? - in detail
The letter "я" should replace the gap in the word "собака" (dog) to form "собака". This is because in Russian, nouns that end with consonants typically require an ending to indicate case and number. For a singular, feminine noun like "собака", the letter "я" is appended to signify the nominative case. Thus, when referring to a single female dog, the word becomes "собака".