I find that when I perform my prayers in Arabic it feels like a chore and I remain unfocused and hurry to finish them, whereas when I recite them in English translation the effects are the opposite. Can I pray in English or in both Arabic and English?
The prayers (Salah) must be recited in Arabic as the Prophet Muhammad (SAWA) recited and ordered all Muslims: Pray as you saw me praying صلوا كما رأيتموني أصلي
If you mean by prayers the supplications (Du'a), it is allowed to recite Du'a in your preferable language. Even you are allowed to read within the Salah supplications in your own language, but that supplications should be along with Arabic parts of Salah.
In short, Salah must be in Arabic but Du'a can be in your referable language.
Wassalam.
Wassalam.