The future 2 is used for assumptions about an action in the past or in the future. It expresses that we think the action took place already or will take place in the future, but we can’t be sure about it.
For assumptions that an action will be completed in the future (Note: this requires a time specification):
⇒ We are speaking about a point in time in the future ("morgen" = "tomorrow"). And by this time, the action will be completed. Since it's talking about the future, we can't be 100% sure, so it's an assumption.
⇒ Important: you always have to include the time!
For assumptions about an action in the past:
⇒ The action has to have been completed (or we think it has been completed!) by the present time → werden + perfect tense
We use "sein" or "haben" based on the main verb. Choose the same verb that you would if you were constructing the perfect tense.
⇒ Condition, state, or location change, as well as "sein," "werden," and "bleiben": use "sein" as the helping verb
⇒ All other verbs and all reflexive verbs: use "haben" as the helping verb
Warning: For conditions / states, always use "sein." The condition will change from the time of speaking to the point in time that is mentioned.
⇒ Change in Condition ⇒ „sein“
Talking about the present: The Simple Present.
When using verbs, word order is important: Main Clauses
Some verbs have to separated when you conjugate them: Separable Verbs.
Learn about modal verbs and what's so special about them: Modal Verbs.
Some verbs are always followed by a specific case: Verbs with Complements.