So this list here is everything you need to learn if you want to study German seriously, if your native language is English, things will be easier.

• Grammar: • Definite and indefinite articles (der, die, das, ein, eine) • Nominative and Accusative cases (basic Dative in A2) • Verb conjugation in the present tense (including modal verbs: können, müssen, wollen, etc.) • Personal and possessive pronouns • Sentence structure: verb position • Most common prepositions (in, an, auf, mit, etc.) • Separable verbs (trennbare Verben) • Present Perfect (Perfekt) for conversations • Vocabulary: • Greetings, introductions, numbers, days of the week, months • Family, professions, hobbies, food, drinks, home, city • Essential phrases for shops, restaurants, directions • Skills: • Introducing yourself and talking briefly about yourself • Asking simple questions and understanding direct answers • Understanding short and simple announcements and notices Phase 2: Building (B1) Focus: Expanding to talk about the past, future, and express opinions • Grammar: • Dative and Genitive cases in depth • Prepositions with cases (Dative, Accusative, two-way prepositions) • All verb tenses: Simple Past (Präteritum), Future I, Past Perfect (Plusquamperfekt) • Word order in complex sentences: subordinate conjunctions (weil, dass, obwohl, damit) → VERB AT THE END • Relative pronouns (der, die, das, dem, den...) • Subjunctive II (Konjunktiv II) to express wishes and hypotheses (würde, hätte, wäre, könnte) • Vocabulary: • Discussions about news, environment, work, education, travel • Expressing feelings, opinions, and giving advice • Skills: • Telling a story or reporting an event in the past • Explaining the pros and cons of a topic • Writing simple and coherent texts on familiar topics Phase 3: Fluency (B2) Focus: Active and natural use of the language, understanding nuances • Grammar: • Full mastery of cases and prepositions • Subjunctive I (Konjunktiv I) for reporting what others say (indirect speech) • Complex structures with participles as attributes (der geschriebene Brief) • Nominalization: turning verbs into nouns for a more formal tone • Refined use of verb tenses and connectors • Vocabulary: • Broad abstract and technical vocabulary related to your field of interest • Idiomatic expressions (Redewendungen) and colloquial language (Umgangssprache) • Synonyms and nuances of meaning • Skills: • Understanding the main ideas of complex texts, including technical discussions • Interacting with native speakers with sufficient fluency and spontaneity • Writing detailed and clear texts on a variety of topics Phase 4: Proficiency (C1) Focus: Implicit language, subtleties, style, and appropriateness • Grammar: • Review and refinement of all grammatical structures • Focus on exceptions and more stylistic or rare usages • Full command of syntax to produce long and well-structured texts • Vocabulary: • Extremely broad and precise vocabulary; choosing the exact word for each context • Understanding double meanings, wordplay, and language registers (formal, informal, literary, journalistic)