Add punctuation: This square is reached by going further towards the sea Behind Plaza Sant Jaume where one can find the Palau de la Generalitat is this small square
A: This square is reached by going further towards the sea. Behind Plaza Sant Jaume - where one can find the Palau de la Generalitat - is this small square.

Add punctuation: His mother was Livia Drusilla a cousin of his father and a very young bride
A: His mother was Livia Drusilla, a cousin of his father and a very young bride.

Add punctuation: The productivity is 213 per cent of the usual level
A:
The productivity is 213 per cent of the usual level.