Incorrect spelling, explanation: quite a common mistake made by English users is to spell the form stays as stayes, which is wrong. It is true that when a verb ends with -y, we change it to -i and then add the -es ending. In the case of stays, however, there is a vowel before -y so we only add the -s ending.

Correct spelling, explanation: grammatically, stays can be classified as a verb, in the third form singular of the Present Simple tense, or as a noun in a plural form. The origin of the word is stare, which was a Latin form meaning to stand. The word stays, however, entered English directly from Old French, in the times of Middle English.

Definition of stays:
1. verb (3rd form singular of the Present Simple) – to be in a place for some time; not to leave a place or some situation;
Every time she visits Barcelona, she stays in the same hotel in the Old Town.
He is a computer programmer so he stays at home most of his time.
2. noun (plural) – spending time in a place;
We had some great stays in different hotels in Paris on our last holiday.

Phrasal verbs and idioms with stays:
Some common expressions include:
1. stays in – to stay at home;
She stays watching TV most of her weekends.
2. stays up – to go to bed late;
When it’s Friday and Saturday he always stays up late.
3. stays loose – to stay calm and relaxed;
He has a really stressful job, but somehow he stays loose.