它们在引导条件状语从句中都含有“如果”的意思，主要区别如下：
providing that 、if、 provided that 当“如果”讲引导条件状语从句时，providing/provided ( that)比if正式，更文雅。更具特点是：提出条件者坚持或要求该条件必须实现的倾向性。
provided ＝no condition that ＝providing that 译为 如果，假如
if也译为 如果，假设，较口语化。
I’ll go providing/provided ( that) the children can come with me.
如果（要是）孩子们能跟我一起去，我就去。
I’ll agree to go providing/provided ( that) my expenses are paid.
假如为我负担费用，我就同意去。
They may swim providing/provided ( that) an adult accompanies them.
如果有成年人陪同，他们就可以游泳。
You can borrow my bike providing/provided ( that) you bring it back.
你可以借我的自行车，只要你还给我。
I shall go provided that it doesn't rain.
假如不下雨我就去。
Provided/Providing that you reduce the price, I'll take all the goods.
假如你减价,我会买下所有的货物。
Provided/Providing that we have adequate supplies, the enemy can never break in.
若有充足的给养，敌人是打不进来的。
I will come providing/provided ( that)I am well enough.
只要我身体好一定来。
Provided/Providing that circumstances permit, we shall hold the meeting next week.
只要情况允许，我们下周将举行会议。
Provided/Providing that you clear your desk by this evening, you can have tomorrow off.
如果你到今晚可以把手头上的工作做完，你明天就可以休息。
Any two persons may marry in Scotland providing/provided ( that) both persons are at least 16 years of age on the day of their marriage
在苏格兰，如果双方均年满16岁就可以结婚。
We shall do this test provided（或providing）that the weather is fine.
只要天气好，我们就做这个实验。
比较：
If you look at the notice, you’ll see it says “No camping.”.(正)
Providing/Provided ( that) you look at the notice, you’ll see it says “No camping.”.(误)
如果你看见了通知，你就会明白：禁止野营。
说明：you look at the notice并不是说话者坚持要求必须实现的条件，所以不能使用providing/provided ( that)；可以使用if。
由于providing/provided ( that)所具有的这一特点，它不能引出说话者所否定或不赞成或不愿其实现的条件：
（错）He used to get angry providing/provided ( that) our dog went into his garden.
他常常因为我们的狗进入他的花园而大发雷霆。（改为if）
（错）I will not help you providing/provided ( that) you do not ask my help.
如果你不向我求助我就不帮助你。（改为if）
在用providing/provided ( that)的地方可以用if 替换。反之，则不尽成立。说得更露骨一点，就是如果你搞不清楚该用哪一个词时就用if,可以包打天下的。
还要注意一下由于provided that 和 providing that 作连词用时 that 常省略，注意别与动词provide（供给）的过去时、过去分词和现在分词混淆。判别时主要根据 provided 或 providing 后面是否有一个从句。如果后面不是从句，则需要根据主语的时态来进行变化哦。
请看例句：
We are well provided with food and clothing. 我们衣食供应充足。
（provided后面不是从句，根据前面有are，可判别出它是过去分词。）
Local businesses have provided financial support.
当地企业提供了财政资助。
Education is provided by the state as of right.
受教育是国家赋予每一个人的权利。
His articles provided the main impetus for change.
他的那些文章是促进变革的主要推动力。
Day care is provided by the company she works for.
她工作的那家公司有日托。
