Can an oath be made on a Rabbinic Mitzvah? i.e a person says they won't light Shabbat candles

Can a person vow not do a mitzvah? What about an oath not to do a mitzvah?

The mutual obligation in a marriage for intimacy and the scope of the requirement

Does a neder mean that the goods of this world are bad or is there another way to look at it?

Can one associate a neder with a firstborn animal? How do Shabbat and Yom Tov receive their sanctity?

Halachot and customs of the yartzheit

Does a vow count if it's made on condition?

What language may a vow be made in? Can Shema and Tefilla be recited in any language?

The Rabbis disdain and discouraging teachings against making vows

Can one send a shaliach to dissolve a vow on their behalf? Does this work for hatarat nedarim?