Not going into first gear

Ive noticed this a few times now when am driving and come to a stop it sometimes won't go into first gear but most of the time it's fine and selects first gear it just happens now and again there's no crunching at all what can I check to eliminate things hope its not the gearbox

how far from floor is the biting point on clutch pedal
more or less than 1'' ?

Just been out to my car the biting point seem ok about 1 1/2 inch from floor, had a look under bonnet to make sure slave cylinder no leaking seems all ok
1 thing I did notice when checking clutch fluid was the colour of it was brown dose that seem right the level of the fluid was ok

Clutch fluid should be pretty clear as its break fluid it uses maybe work draining and adding fresh fluidd and bleeding the clutch and see if that's any better

yes it may well be contaminated.
buy some dot 4 fluid and drain the old fluid out completely and refill and bleed it, then see how you get on

Thanks guys will try that where best place to drain all the clutch fluid from
Or shall I undo the slave cylinder nipple and drain from there while toping up with new fluid until clear fluid comes through

Thats how i did mine from the slave cylinder nipple then kept topping it up until the new fluid come through .

Great guys that's a job for the weekend then

Mine came out black the other weekend, had a few problems with the clutch / gearbox before flushing and now with a slight adjustment of the pedal everything is sweet as a nut!