Ki Tavo 5778

The purpose of Bikkurim, hakarat hatov, and the importance of doing mitzvot with joy, especially giving tzedakah.

Why is the third year called "שנת המעשר" - the year of Maaser?

Oznaim L'Torah: why do we give maaser sheni twice as often as maaser ani?

Why is the statement made called Vidui Maaser, what does it have to do with confessing?

Why do we need a second Tochacha? Why is the Tochacha in Ki Tavo in the singular while the Tochacha in Bechukotai is in the singular?