Assume the statements are true even if they seem odd, and decide which conclusions definitely follow. Venn diagrams are the safest method.
1Rules
All A are B ⇒ Some A are B, and Some B are A (conversion)
Some A are B ⇒ Some B are A
No A is B ⇒ No B is A
All + All ⇒ All; All + No ⇒ No; Some + All ⇒ Some
Two 'some' statements or two negative statements give no definite conclusion
2Either–or case
If two conclusions are about the same two groups and one says 'some are' while the other says 'no' (or 'all' vs 'some … not'), and neither follows, then 'either I or II' follows