$\text{1.}$ His girlfriend will be introduced by him on his next birthday.
$\text{→}$ Câu bị động thì TLD: S + will be + Ved/ P2 + (by)
$\text{2.}$ She asked me when I would return the books to the library.
$\text{→}$ Câu tường thuật
$\text{→}$ will ⇒ would
$\text{3.}$ Unless you try hard, you won't pass your final exam.
$\text{→}$ Câu đk loại 1: If + S + V<s,es>, S + will/ can/ may + V.
$\text{→}$ Unless = If not
$\text{4.}$ I wish I had taken my doctor's advice.
$\text{→}$ Câu cầu ước trái với QK: S + wish<es> + S + had + Ved/ P2.
$\text{5.}$ I don't know as much as she about it.
$\text{→}$ (not) as ... as: so sánh (ko) ngang =
$\text{6.}$ Although my sister was tired, she helped me with my homework.
$\text{→}$ Although + S + V, S + V: Mặc dù