Use the ending first, then the pronoun.
1. If the form ends like يَفْعَلُ، تَفْعَلُ، أَفْعَلُ، نَفْعَلُ, place it in the first group.
2. If it ends with the inflectional nūn in ـانِ، ـونَ، ـينَ, place it in the second group.
3. If it is يَفْعَلْنَ or تَفْعَلْنَ, place it in the third group.
4. For repeated written forms, use the pronoun or context to identify the exact slot.
Together these checks complete the grouping of all fourteen slots.