Final answer:
The infinitive stem of "saber" for conjugation in the future and conditional tenses is "sabr-".
Step-by-step explanation:
The infinitive stem of "saber" in the future and conditional tenses is "sabr-". When conjugating "saber" for future or conditional tenses, one would use the respective endings with this stem. For example, "sabré" (I will know) in the future tense, and "sabría" (I would know) in the conditional tense.
The formation of these tenses is consistent across all verbs, with the infinitive stem being used as a foundation upon which the respective conjugational endings are added.
In these tenses, the endings are added to the stem to form the conjugated verb.
For example, in the future tense, the verb saber (to know) becomes sabr- + é for the first person (yo) singular: sabré (I will know).
In the conditional tense, the verb saber becomes sabr- + ía for the first person (yo) singular: sabría (I would know).