السلام عليكم ورحمة الله وبركاته شيخنا أحسن الله إليكم Is it permissible to change the wording of supplications reported in the Shari‘ah from plural to singular, or from singular to plural (even if addressing one person)? For example, from جزاك الله خيرا to جزاكم الله خيرا بارك الله فيكم

Ustadh AbdulAziz al-Haqqan

Yes, if you are making dua for yourself, then you say it in the singular. If you are making dua for a group that are with you, then you say the dua using the plural.