Can't get any more lessons

[HananQubati]

I am now in level five and done with the " adjective" section . But now I am no more able to get any next classes !
What went wrong ?

[psionpete]

Have you completed all the lessons? And turned all the skills up to that point gold? That is usually the problem with unlocking subsequent skills.

[HananQubati]

I still have 2 uncompleted lessons ! so that might be the problem
thank you much psionpete for informing me .