Geometry help? Similar polygons

I know the properties but I get confused on this sometimes always and never stuff. It is too subjective. Please help.


Two isosceles triangles are _____ similar.

2.
Two regular polygons are _____ similar.

3.
Two squares are _____ similar.

4.
An isosceles and a scalene triangle are _____ similar.

5.
A right triangle and an isosceles triangle are _____ similar.

6.
Two equilateral triangles are _____ similar.

1. Sometimes
2. Sometimes
3. Always
4. Never
5. Sometimes
6. Always

I hate these types of questions too :/