Many languages mark the future with a small particle attached to the present-tense verb, leaving the verb's form untouched. German takes a different route: it uses a full auxiliary verb, werden (literally "to become"), conjugated according to the subject, while the main verb moves to the very end of the sentence in its unconjugated infinitive form. This structure is Futur I: conjugated werden in its normal second position, main verb in its base form at the end.
Example: Ich werde morgen nach Berlin fahren — werde is conjugated for ich, and fahren stays unchanged at the end, exactly like the modal verbs (Modalverben) from A2, such as ich kann fahren. If you've mastered word order with modal verbs, you already know Futur I's structure without realizing it.
The real surprise is that German speakers rarely use Futur I in everyday conversation. When a time expression already signals the future — morgen, nächste Woche — speakers simply use the present tense (Präsens): Ich gehe morgen ins Kino instead of Ich werde morgen ins Kino gehen. Both are correct, but the first is far more natural. Futur I is reserved for specific situations: a firm promise (Ich werde dich nicht vergessen), a prediction (Es wird morgen regnen), or insistence (Du wirst das jetzt machen!).
A further twist: with a word like wohl or sicher, Futur I isn't about the future at all — it expresses a guess about the present. Er wird wohl krank sein means "he's probably sick right now," not "he will be sick tomorrow."
Futur II (werden + past participle + haben/sein) is rare, used to say an action will already be complete by some future point, as in Bis Ende des Jahres werde ich Deutschland erreicht haben. Don't worry about it much at this level.
A common mistake is overusing werden in every future sentence, treating it as a direct equivalent of a future particle. Usually the better choice is present tense plus a time expression, saving werden for genuine promises, predictions, or emphasis.