`3.` As soon as I see him tomorrow , I will give him your letter

`-` As soon as +  S +  V(s/es) + O,  S +  will +  V_inf + O : ngay khi

`4.` These new rooms are theirs

`-` TTSH + N `=` ĐTSH

`5.` Minh said that he would send his email to the teacher the following day

`-` Câu tường thuật:
S  +  said  + (that) + S  +  V(lùi thì)

`-` will `->` would

`-` tomorrow `->` the following day/ the next day

3. As soon as I see him tomorrow, I will give him your letter.

As soon as+ HTĐ, TLĐ: ngay khi 

4. These new rooms are theirs.

S + be + DTSH 

5. Minh said that he would send his email to the teacher the next day.

S + said (that) + S+ V (lùi thì)

will --> would 

tomorrow --> the next day / the following day 

`color{orange}{~MiaMB~}`