When \$V_{GS}\$ is very negative \$I_D=0\$, whereas it conducts a little current when \$V_{GS}\$ is a little negative.
What is the value of \$I_D\$ when \$V_{GS}=0\$?
When \$V_{GS}\$ is very negative \$I_D=0\$, whereas it conducts a little current when \$V_{GS}\$ is a little negative.
What is the value of \$I_D\$ when \$V_{GS}=0\$?
The value of \$I_{DS}\$ when \$V_{GS}=0\$ is called \$I_{DSS}\$ on datasheets.
Consider for example the following excerpt from Supertex DN3545 datasheet.