How to use 'may'

In English, the word ‘may’ is generally used in two quite distinct ways:
1) to give permission:

• “You may leave when you have finished typing the document” {= “you have permission to leave when you have finished typing the document”]
• “Candidates may bring a calculator into the exam” [= “Candidates have permission to bring a calculator into the exam”]

2) to express the possibility of something happening (generally when we use ‘may’ like this, we communicate the idea that something is not very likely to happen, or we are not very sure about it):

• “It may rain tomorrow” [= “it is possible that it will rain tomorrow”]
• “She may not like the new uniform” [= “it is possible that she will not like the new uniform”]

It is important to keep these two uses of ‘may’ quite separate. In a sentence, ‘may’ should either be used to give permission, or to communicate the idea of possibility. It can’t do both at once.
However, in Hong Kong English, some speakers mix up these two uses of ‘may’.

Consider this sentence from a government document, for example:

• To help give the right answer for you, we may need to ask for some information from you. Please select the answer that applies to you when the screen below asks you to make a choice. You may click on the question if you need to start over.

​
You’ll notice that this passage uses the word ‘may’ twice, in two different sentences. Take a look at each one and ask yourself whether it is type (1) use of may (permission), or type 2 (possibility or likelihood).
You should have found that in the first sentence, ‘may’ is clearly a type (2) usage; the sentence could be rewritten as “To help give the right answer for you, it is possible that we will need to ask for some information from you.” 
However, the second sentence is not so simple. Does it mean “it is possible that you will click on the question if you need to start over”?  No, it can’t mean that. The writer is not trying to guess what the reader will do. So, does it mean “You have permission to click on the question if you need to start over”? This doesn’t really make sense either, because the writer is not in a position to give permission to the reader. What the writer simply wants to do is tell the reader about an option that is available to them. In standard English, we would simply express it in one of these ways:

• Click on the question if you need to start over.
• Simply click on the question if you need to start over.

In summary, ‘may’ is incorrectly used in the second sentence. This incorrect usage of ‘may’ is quite common in Hong Kong English, as you can see in the following examples:

• The current exhibition is held from 18 to 20 July 2014 at G/F Domain, Yau Tong. FREE admission from 11am to 8pm. Visitors may receive a souvenir and design a unique yet creative sticker.
• Each participant may submit more than one (1) logo design. Participants may refer to this website for detailed information about the Charter scheme for reference.
• Interested person may send their curriculum vitae to HKAS Executive.

In every one of these cases, ‘may’ is used incorrectly and not according to the type (1) or type (2) meanings given at the start of this post. It seems that in Hong Kong English, ‘may’ is often used (as here) to try to communicate politeness and avoid giving a direct instruction. But in standard English, ‘may’ is not used in this way. Here are the sentences again, now rewritten in standard English:

• The current exhibition is held from 18 to 20 July 2014 at G/F Domain, Yau Tong. FREE admission from 11am to 8pm. Visitors will receive a souvenir and design a unique yet creative sticker.
• Each participant may submit more than one (1) logo design. Participants should refer to this website for detailed information about the Charter scheme for reference.
• Interested person should send their curriculum vitae to HKAS Executive.