I found it really difficult to learn how to say things like,
I would always come up with, for example: ‘não posso esperar’ — which translates quite literally to ‘I am unable to wait’
To express the true meaning of hardly /barely etc, use MAL. This may seem counter-intuitive as mal can have other loaded meaning such as evil, wrong, bad…
Here’s how to use it for hardly, barely etc:
I can hardly wait. >> Eu mal posso esperar.
He can hardly walk. >> Ele mal pode andar.
She was barely able to speak. >> Ela mal podia (conseguia) falar.
He was hardly able to do it. >> Ela mal conseguia faze-lô.
* Remember, it’s mal+poder or conseguir to say anything like this.