Gears struggling to get into third

[AmberKenyon]

I have a VW Polo '07 plate. My car has recently started stopping me going into third gear occasionally, and slipping into first which is terrifying. Sometimes its fine. This is my first car, and i've only had it for 6 months. I've been told it is likely to be a gear linkage problem or a gear box issue- I know one is much more expensive than the other. I was wondering if anyone could give me some advice, or whether anyone has had a similar issue. Thanks.

[RUM4MO]

Well the gear selection adjustment will be easier and cheaper to try first, I'm sure that there is a youtube video of how to do it - look for Volkswagen gear change adjustment, or something like that.