$\text{@su}$
Câu `1`: The explanation was so difficult that I couldn’t understand it
`→` The explanation was too difficult for me to understand it.
`⇒` S + tobe + so + adj + that + S + V
= S + tobe + too adj + for sb + to V
Câu `2`: I felt very tired so I went to bed early
`→` I went to bed early because I felt very tired.
hoặc I went to bed early because of being tired.
`⇒` clause 1 + so + clause 2 = clause 2 + because + clause 1 = clause 2 + because of + N/V-ing
$\text{#BTS}$