
Stephanie C. answered 09/14/21
Fluency that Lasts | Certified Chinese Teacher, Tailored Lessons
信得过 (able to trust) is a resultative compound in potential form. The negative form of it is 信不过 (unable to trust.)
你是我的好朋友,我当然信得过你。(You are a good friend of mine. Of course I can trust you.)
那个人我不认识。我信不过他。(I don't know that person. I can't trust him.)
You are right, 信 means "to believe" or "to trust." 过 has many meanings such as "to pass" or "to surpass." Here, it is a resultative ending that has already lost its original meaning and must be memorized. And the "得" and “不" in “信得过” and "信不过" are particles indicating the potential form.