totemo an takusan
is "totemo" only used to modify an adjective?

and may "takusan" be used to modify nouns as well as verbs?

nihongo wo takusan/totemo manabitai.
kare wa takusan/totemo benkyoushiteru.

wich is correct?

Question

totemo an takusan
is "totemo" only used to modify an adjective?

and may "takusan" be used to modify nouns as well as verbs?

nihongo wo takusan/totemo manabitai.
kare wa takusan/totemo benkyoushiteru.

wich is correct?

Answer

nihongo wo takusan  manabitai.
I want to study a lot of japanese.

nihongo wo totemo manabitai.
I really want to study japanese.
 
kare wa takusan/totemo benkyoushiteru. 
both is ok,same mean.
he is studying Japanese very much.

"takusan+noun" is incorrect.
"takusannno+noun" is correct.