How can enforce and reinforce have slightly different spelling and still be valid?

When I initially wrote inforce the dictionary told me that enforce was the correct word.

However, when I wrote reenforce it told me that reinforce was the word I was looking for.

So, I searched this on-line, but didn't find anything useful except this post

Can someone elaborate on this further?

Solution 1:

The reason the spellings are different is that reinforce does not mean "to enforce again". The word enforce is defined by the Macmillan dictionary and others as

to make sure that a law or rule is obeyed by people

or

to make sure that something happens or is done

Reinforce, however is defined as

to make an idea, belief or feeling stronger

or

to make a situation, process or type of behaviour stronger and more likely to continue

or

to make a building, structure or object stronger

or

to make a group of soldiers, police etc stronger by adding more people or equipment to it.

In short enforce means to ensure that a law or rule is obeyed or complied with, while reinforce means to make something stronger in some way.

There is no word "to inforce" meaning to make strong initially, if a building is made strong initially, say by the use of reinforced concrete in its construction it is said to be "strongly built" and, if it is later strengthened, it is then said to be reinforced.

Similarly there is no word reenforce meaning to enforce again, perhaps after a regulation has been allowed to lapse. If it was needed it might be hyphenated to give re-enfoce but the situation probably does not arise frequently enough for such a word to become universally understood.