• Chen is pronounced as "chen" with a falling tone, similar to the "ch" sound in the English word "church", but with a more retroflex initial.
• Tian is pronounced as "tee-en" with a rising tone, similar to the "tee" sound in the English word "tea" and the "en" sound in the English word "pen".
• Yu is pronounced as "yoo" with a flat tone, similar to the "u" sound in the English word "put".

So, the full pronunciation of 陈天宇 (Chen Tian Yu) is "chen tee-en yoo".