"1 .. they have a mouth full of food ..
2 .. they simply don't feel like it ..
3 .. the other person been asking tooooo many questions .. probing toooo deep ..
wanting to know why this and why that .. .. they generaly don't like other folk probing into their private business
4 .. they get the feeling that they are being 'pushed' in some way
6 .. there sick and tired of the constant yakking (excessive meaningless talk) from the other person ..."
"- they're not sure how to answer you or talk to you, so they just *don't know how* to talk to you..."
See some more reasons a Taurus is silent @ Linda Goodman's forum