Does the computer only runs one programming language at time?

Answer 1

If it is interpreted or bytecode language, it needs an interpreter or virtual machine, one per process eg one per one command line window.
In many languages you can from main programme call other language programmes if these second are translated to native binary code.
It is possible to run programs in different languages each in different processes (eg window), and let communicate it eg with shared files, or with a net protocol.

Answer 2

What do you mean exactly by 'one programming language at time'?

Answer 3

i mean like can I use two programming languages for making just one code