Muslims who do not speak Arabic.

Anatolian,

In answer to your question. I know what I am saying in Arabic regarding the prayer, as I learnt it in English first. There was no way I could be happy about praying if I didnt understand it in my own language first.

When I read the Quran I use an English translation.

Of course I cant answer for born muslims whose natural tongue is not Arabic.

Previously, as a Christian, all prayers came from the heart, and were not written down.  As Angela said :- know what the prayer means instead of just saying the words, Prayer needs intention and attention.

The same applies again for dua's, an individual muslims prayer

I do not know Arabic. I will learn it though, Insha'Allah!

I know what I am saying when I perform my Salat in Arabic. When I was in the learning phrase of memorizing Salat, I would write down one sentence In arabic. Then next to it I would write it in English. I think it is very important that we know what the meanings are, before we utter anything in Arabic, or any language for that matter. How could it be from the heart if we do not know what it mean?!

When I first started performing salat. I would first say it arabic then I would perforn the prayer over again in English. I continued to do that until I knew all the meanings of rakats I was performing.

 The prayer special parts are compulsory to be recited in Arabic. But in Sajadah or otherwise, at any time, the prayer can be in own language (after the fixed Arabic words), like beseeching Allah for something. It can be done in own language, Urdu, English, Hindi etc.

 During Sajadah (prostration) or Rukuh Quranic verses should not be recited.

 Whether any one understands the Arabic words or not, there is no danger because the words are remembered by heart and they do not contain anything bad. The same words are used all over the world for centuries. The meaning can be understood slowly.