-ir and -er ending verbs are very similar in their endings when they are conjugated. How often do they differ in their endings when they are conjugated.

Ir and -er ending verbs usually have different endings when they are conjugated. However, there are some specific verb forms where their endings can be similar. Here are a few examples:

1. The nosotros/nosotras form in the present tense:
- For -ir verbs: The ending is -imos (e.g., vivimos, we live).
- For -er verbs: The ending is -emos (e.g., comemos, we eat).

2. The future tense for all pronouns:
- For -ir verbs: The ending is -iré, -irás, -irá, -iremos, -iréis, -irán (e.g., viviré, I will live).
- For -er verbs: The ending is -eré, -erás, -erá, -eremos, -eréis, -erán (e.g., comeré, I will eat).

Overall, although they have some shared endings in specific verb forms, ir and -er ending verbs generally differ in their endings when conjugated.