Google精确搜索结果：if it wasn't for出现次数51m（m为百万），if it weren't for 24m，if it were not for 17m，were it not for 10m。千问AI说正式文体用were不用was，正确！正式程度：“were it not for” > “if it were not for” > “if it weren’t for”，但were it not for显得老式。