Verb-subject agreement

From Al-Duroos

If the verb precedes the subject, then the verb must be in the singular plural form, but needs to agree in gender.

For example:

ذهب الطلابُ الى نيو يورك

ذهبتْ البنات الى الحديقة

The verb may also be positioned after the subject. In that case, the verb will agree in gender and number.

For example:

الطلابُ ذهبوا الى نيو يورك

البناتُ ذهبنًّ الى الحديقة

Which word order used is a matter of style.

The plural form of the verb (even when preceding the subject) is also used when the subject has been previously mentioned in a previous sentence or clear from the context.