Statements : All animals are birds. Some animals are human beings. Conclusions : I. Some human beings are birds. II. Some birds are human beings.

First Premise is Universal Affirmative (A - type).
Second Premise is Particular Affirmative (I - type).
Some human beings are animals. ↔ All animals are birds.
I + A ⇒ I-type of Conclusion "Some human beings are birds".
This is Conclusion I.
Conclusion II is converse of it.