It is easy to make a verb negative in Persian. The prefix “نـَ” negates all of the verbs. If the verb starts with “می”, the negative prefix changes into “نـِ”.
به خانهتان آمدم امّا نبودی.
من گوشت نمیخورم.
آنها پول ندارند.
امروز صبح پستچی نیامد.
I came to your house but you weren’t [there].
I don’t eat meat.
They don’t have money.
The postman didn’t come this morning (literally: today morning).
When the prefix “نـَ” is attached to a verb starting with a vowel like “آمد”, a consonant “ی” (sounding like “y”) comes in between to prevent two vowels being pronounced right after each other. (See the last example above.) In negative verbs, the stress is always on the “نـ” syllable.
The verb “to be” (بودن) somehow undergoes a stem change when being conjugated in the present tense negative form:
[I] am not
[you] are not
[he/she/it] is not
[we] are not
[you (pl.)] are not
[they] are not
As you can remember, there are two different ways for conjugating the verb “to be” in the present simple tense. But the negative form is always the same. Here are some examples:
در اتاق جای نشستن نیست.
تو تنها نیستی.
Zahra is not [here/there].
There’s no place to sit in the room.
You are not alone.
The suffix “ی” in negative sentences
In a negative sentence, the object can be followed by “ی”. The suffix “ی” here means “any”.
I don’t know anything.
We didn’t eat any food.
No problem! (Literally: It doesn’t have any problem.)