Since all trees are plants and no animal is a plant, logically no animal can be a tree.

From two 'some' statements, we cannot draw a definite conclusion about the relationship between singers and actors.

Although all gold is precious, only some precious things are expensive, so we cannot definitively conclude gold is expensive.

Since no criminal is honest, it means all criminals must be dishonest (contrapositive of the first statement).

Since some decision makers are not politicians, and all leaders are decision makers, some leaders must not be politicians.

While no student is lazy, and lazy people are unsuccessful, this doesn't tell us about unsuccessful students who might be lazy or for other reasons.

Since all X are Y and no Y is Z, by logical deduction, no X can be Z.

While some problem solvers are not creative, some software engineers might still be creative - this is possible but not definite.

We know some educated people are rich and no rich person is unhappy. Since some doctors are educated (subset), some doctors could be among those rich people, making them not unhappy.

All flowers are plants, all plants require sunlight. Since some things requiring sunlight are expensive, it's possible that some flowers (being things requiring sunlight) are expensive.