如果他在這兒,一切都沒問題了.
all right
這是if引導(dǎo)的虛擬語氣
1.表示與現(xiàn)在事實相反的情況,其句型為“ if+ 主語 + 動詞的過去式（ be 動詞用 were ）,主語 +would / could / might / should + 動詞原形”.如：If the weather were fine,we would go to Shanghai.如果天氣好,我們就去上海.（事實上天氣不好） If they had time,they would / could / might go with me.如果他們有時間,他們就會（可能）和我一起去.2.表示與過去事實相反的情況.其句型為“ if + 主語 + 動詞的過去完成式,主語 +would / could / should / might + have + 動詞的過去分詞”.如：If I had taken his advice,I shouldn't / wouldn't / couldn't have made such a mistake.如果我按照他的建議去做,我一定不會（不可能）犯這樣的錯誤.3.表示與將來事實可能相反的假設(shè)和結(jié)果,其句型為“ if + 主語 + 動詞的過去式 / should + 動詞原形 / were to +動詞原形,主語 +would / could / might / should + 動詞原形”.如：The glass would break if you dropped it.杯子摔下來會打破的.（事實上沒有摔下來） If it should rain,the crops would / could / might be saved.假如天下雨,莊稼就一定（有可能）會得救.