i had a thought today i have a team full of great foreign players but they always underachieve does anyone no if a launguage barrier is involved or i m just useless

well if a player is unsteled because he's homesick or doesn't speak the languege they do realy bad on the pitch

so they might underperforme because this

Go to your Assistant Manager screen and look at Team Report. There should be an assessment from the AssMan as to how well the team works together. (I'm still at work, so I don't have the exact details.)

The assessment will tell you how well the team understands each other. If their understanding is low, you may have a problem. It could be low because you bought a whole lot of new players or you don't play the same team and tactic week in, week out.

The more nationalities and languages, the harder it will be for the team to gel.

I agree with the above post. Also worth taking into account is if you've made multiple signings in a short space of time. Players do need time to gel regardless of the language, although obviously if you have a multi-national squad, over time, they will start to speak the local language and therefore also become more settled.

With this in mind, there could also be the "adaptability" value in effect. You may unfortunately have a squad full of players with low adaptability