这句话后面那个inIaminterestedinforeignlanguage,especially(in)Chinese.我对外语感兴趣,尤其是对汉语.（老外说）Iaminterestedinmath,especially(in)partialdifferentialequations.我对数学感兴趣,尤其是偏微

Question

这句话后面那个 in
I am interested in foreign language,especially (in) Chinese.
我对外语感兴趣,尤其是对汉语.（老外说）
I am interested in math,especially (in) partial differential equations.
我对数学感兴趣,尤其是偏微分方程.

Answer 1

I am interested in foreign language,especially (in) Chinese不需要
I am interested in math,especially (in) partial differential equations.需要