Two similar triangles are congruent always, sometimes, or never?

I think the answer is: sometimes

congruency means, exact twins, completely exact.

similarity means, they must look the same only, one can be larger or smaller than the other, the angles must be the same, but the lengths can be longer or shorter and that's ok.

if two figures are congruent, they are also similar, but if one is larger than the other, they're still similar, though not congruent anymore.