I went to drive my 2002 focus 1.6 and could not select a gear with engine running, however when engine is off I can select gear but when I start car with foot on clutch the car just pulls off. Does anyone know what the problem might be and roughly how much to repair. 

This is known as clutch drag, basically the clutch no longer disengages properly.

It's possible there's air in the hydraulic line but usually the clutch will be knackered and need replacement.

I only had a new clutch last October so I didn't think it would be that.

3 minutes ago, Simondeakin123 said:

I only had a new clutch last October so I didn't think it would be that.

Well there's nothing else it can be.  Was it a 3 piece clutch kit that was changed?  What brand parts were used and did you get a warranty with it?  

I had it repaired by a friends dad who owns and run a garage but only got a receipt for the cost no description of work carried out or parts used so I guess i got to pay out again.

you might be lucky and it is the clutch master cylinder that is faulty.  when you put your foot on the clutch pedal it pushes a rod into a hydraulic cylinder on the bulkhead in front of the clutch pedal. that pushes fluid through a pipe into another cylinder in the clutch to disengage it.  if either cylinder is faulty it can let fluid out and air in. If air gets in where the fluid should be then the clutch will not disengage. 

But it could be clutch itself.

I am not sure of the arrangement on this car, some cars have one fluid reservoir that feeds the clutch and brakes. so that clutch leak can not cause brake failure, the clutch takes fluid from a point higher up the reservoir than the brakes does.  But that can mean that if the brakes are leaking fluid, the clutch suffers first from lack of fluid from the reservoir. 

It needs someone to investigate further. 

But I have known clutch parts to break suddenly (not just gradually wearing out) and hence need replacing

Thanks for the reply I guess I will just have to get someone to look at it. Hopefully it's not to expensive.

59 minutes ago, Simondeakin123 said:

Thanks for the reply I guess I will just have to get someone to look at it. Hopefully it's not to expensive.

Whats your brake fluid level like?