The source identifies four letters that begin the present-tense forms. Their distribution across the 14 slots is systematic.
Sign
Forms
Where it is used
ي
4
Three third-person masculine forms and the third-person feminine plural
ت
8
Third-person feminine singular/dual and all six second-person forms
أ
1
First-person singular
ن
1
First-person plural
The first letter is important, but the ending is also needed to identify the complete form.
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Present-Tense Verb: Signs and Three Paradigms
The source identifies four letters that begin the present-tense forms. Their distribution across the 14 slots is systematic.
Sign
Forms
Where it is used
ي
4
Three third-person masculine forms and the third-person feminine plural
ت
8
Third-person feminine singular/dual and all six second-person forms
أ
1
First-person singular
ن
1
First-person plural
The first letter is important, but the ending is also needed to identify the complete form.