英语合同中，除了if之外，引导从句表示“如果，假如”，经常用到 if and whenever, in the event that/of, where, should, in case/in case of,provided that， on condition that/on the conditions that, insofar as等引导词。具体使用方法可以参考以下例句。

例如：In case part of or all know-how of the above mentioned technical contents have been published by Party B or Third Parties and A obtains evidence of such publication, then Party A shall no longer be responsible for keeping secret and confidential the part already published. ( 如上述专有技术的一部分或全部已由乙方或第三方公布，而甲方也掌握了已公布的证据，则甲方不再承担保密义务。)

15% of the above contract price, e.g. US $ 21,000.00 shall be paid by Party A to Party B by M/T within 30 days after Party A has received from Party B the following technical documentations and documents, providing that they are in conformity with the contract: ( 甲方从乙方处收到以下技术资料和文件后30天内应信汇乙方上述合同总价的15%，也就是21000美元，但该技术资料和文件应符合本合同要求。)

Either party may at any time replace the chairman, deputy chairman or director(s) it has appointed, provided that it gives written notice to the Joint Venture Company and the other party. ( 任何一方可随时更换自己委派的董事长、副董事长或董事，但必须书面通知合资公司和合资的另方。 )

需要注意的是，provided that通常语气上有转折的含义，不太适合用于表达“假如，如果”;而用于表达“但是”，则较为过渡自然， 符合汉语表达的规范。