`1.` A student who has studied English for a few years may have a vocabulary of thousands of words.
→ mệnh đề quan hệ "who" thay thế cho "he"
`2.` Between formal and colloquial English there is unmarked English, which is neither so literary and serious as formal English nor so casual and free as colloquial English.
→ mệnh đề quan hệ "which" thay thế cho "it"
`3.` Although his friend advised him against it he bought a jeep.
→ Although+clause: mặc dù...
`4.` Though good writing requires general and abstract words as well as specific and concrete ones, it is the latter that makes writing vivid, real and clear.
→ Though+clause: mặc dù... (though đứng đầu để nhấn mạnh)
`5.` It was raining so hard that they could not work in the fields.
→ so adj that: quá ... đến nỗi
$@Ly$
