Correct spelling, explanation: supply is a widely used word in English, which can function either as a noun or as a verb. Supply, however, has a Latin origin as it comes from supplere, which could be translated as fill up. The word actually combined two other Latin words, which were sub, meaning from below, and plere, meaning fill. When it comes to English, supply appeared in it in Middle English.

Definition of supply:
1. verb – to provide something, often in a large amount and over a longer period of time,
It’s a state company that provides electricity for most of the households in the country.
2. noun – something, which is available for use,
The world is so unsettled today that we want to be prepared for the worst and that’s why we store in our basement a large supply of tinned food.

Collocations with supply:
Supply appears in a number of useful collocations, such as: in short supply, water supply, and cut-off supply.
Because of extreme weather conditions, fruit and vegetables are in short supply this year and it’s no wonder that the prices have gone up.
If the government really cared about all the citizens, it would ensure the water supply to all the regions of our country.
The message is clear – if we don’t pay our debts, they will cut off the supply of their products.

Incorrect spelling, explanation: supply has a relatively easy spelling as it is a short word, but still both native speakers of English and its learners often forget that there is a double -p letter in the middle of the word. As a result, a common mistake is to spell supply as suply, which is incorrect.