In his early movies Adam love interests usually had names starting with what letter?

You're likely thinking of Adam Sandler. He often casts actresses with names starting with "D" in his early films. Some examples include:

* Drew Barrymore (The Wedding Singer, 50 First Dates)

* Diane Keaton (Something's Gotta Give)

* David Spade (though not a romantic interest, often a comedic partner)

While not exclusive to the letter "D", it is a noticeable trend in many of his early movies.