Matches in common

[hudsonh]

If I have matches in common with me but they do not match each other on any of the Chromosomes does that mean that their links to me must be through different ancestral lines? Sorry if this question is basic, I'm just beginning.

[dna]

No, they can be from the same line.

Unfortunately, the answer should be: depends (on the level of relationship, amount shared etc.). Try http://www.familytreedna.com/learn/