Он говорит строго (he speaks strictly) => Он говорит строже (he speaks stricter) => Он говорит строжайше (he speaks the strictest) I write the very best in my class. - Я пишу лучше всех в классе. Superlatives of adverbs in the Russian language have a simple and compound form. Simple form - formed by suffixes "-айше" and "-ейше", but this form is rarely used and is considered obsolete. More often used a compound form. The compound form is formed by adding to the adverb the words "наименее" and "наиболее", for example: "наиболее высоко", "наименее сильно". And also it is formed by adding to the adverb particles "всех" or "всего", for example: "быстрее всех", "смешнее всего". против I write the best (material) in my class. - (material) - you mean some kind of report or essay? If it so: I write the best reports in my class - Я пишу лучшие доклады в классе. And about "в моём классе" - often you don't need to say "моём" about the things, that is clearly yours :), in Russian you can say just "в классе". For example: In English you say - "I like to walk with my husband." But in Russian you say - "Я люблю гулять с мужем" without "моим", becouse you're talking about yourself and it's absolutely clear that the husband is yours, not someone else's :)))

Он говорит строго. Он говорит строже. Он говорит строже всех. Я пишу хорошо. Я пишу лучше. Я пишу лучше всех

Он говорит строго. => Он говорит стороже. => Он говорит строже всех. Я пишу лучше всех в моем классе (For both your examples.) В обоих случаях используется составная форма превосходной степени.

"хорошо" ,*лучше*, and "наилучше" (ADVERBS) "хорошое", "лучше", "лучшее" without "самое" (ADJECTIVES) P.S. "лучшее" must never be used with "самое" in written speech, but is sort of OK to use in very casual informal speech.

Don t think only about rules! More talk with Russian speaker and it will be OK!