Thanks. Kindly let me know the difference between these two sentences? Because I think both are in past.
1) We supplied this material on February, 10 2006.
2) We had supplied this material on February, 10 2006.
1) is the imperfect past tense. It means the material was supplied ON THE DAY OF February 10, 2006, which is now in the past.
2) is the pluperfect past tense. It means that the material was supplied on a date BEFORE February 10, 2006. So February 10, 2006 is now in the past, but even ON THE DAY OF February 10, 2006, we could say "We HAVE supplied this material" (present perfect past tense).