Suppose you want to find the Greek verb for “we believe”. Here’s the process you would follow:
We need to find the stem. To do this, look up πιστευω in the back of MBG. There you will see that the code for πιστευω is v-1a(6). (p. 350 middle column). Now you need to find that code. In the outside upper corners of each page of MBG, you’ll see the list of codes. v-1a(6) is on page 253. Notice, the definition given for these verbs “roots ending in ευ…” Now we know that the stem is πιστευ-.
Now add the connecting vowel which leaves you with πιστευο.
Following this process, you’ll be able to build any Greek verb. If you get stuck, don’t hesitate to ask.