Is it permissible to supplicate to Allah during prostration in Qiyam prayer using colloquial language to complain about one's state and express desires, such as: "O Lord, such and such has befallen me, and I wished that such and such would happen, and I am tired, O Lord, and does this please You, O Lord?"?

It is permissible for a Muslim to have an intimate conversation with their Lord and supplicate to Him with whatever they desire, and to complain to Him about their condition, as did the Prophet of Allah, Jacob, and His beloved, Muhammad, peace be upon them both. However, the supplicant must observe proper etiquette with their Lord, and not speak in a way that shows ill-manners, such as objecting to divine decree and destiny. It is preferable for the supplication to be with the narrated (ma'thur) prayers and in classical Arabic for those who do not make grammatical errors. But for those who are unable to do so, or fear losing their humility (khushu'), there is no harm in supplicating in colloquial Arabic or with grammatical errors; for Allah knows the intention of the supplicant even if their tongue is not eloquent, as this was permitted by Ibn Taymiyyah, Ibn al-Salah (definition), and other scholars.