French language Q&A Forum

I have read that if the subject of the secondary clause is the same, that one should not use the subjunctive, instead just use the infinitive.   But i have a sentence where i'm trying to figure out how to do that even though it feels like the subject has to be restated and would require conjugation.  I'm trying to say "Sometimes I feel like i don't know any french", and here's what i've come up with.  Would be great to get some guidance on this, perhaps there's a better way to construct the sentence.  Merci!

Parfois, je me semble que je ne sache aucun de francais.

I noticed in the exercise "droite" was used for direction to the right, but "tout droit" is masculine for "straight ahead.  Why the difference?