René Descartes' saying "Cogito ergo sum" has been widely spread all over the world. In English it is commonly known as "I think therefore I am", but it is also known to us that "therefore" is not a conjunction, and thus the proper sentence should be "I think. Therefore I am" , "I think; therefore I am" or even "I think, and therefore I am".
Regardless of that, I wonder if "I think therefore I am" is not grammatically correct, then how can it be accepted by the whole English world?
Hence how to figure it out?

