Correct spelling, explanation: watches is either a plural form of the noun watch or the third singular Present Simple form of the verb to watch. When it comes to the history of the word, watches probably relates to the form wake, which in Old English had the form of waecce, meaning watchfulness, and waeccende, meaning remain awake. In modern English watches is one of the most popular words.

Definition of watches:
1. verb (3rd singular form) – to look at something for some time,
She watches the same series over and over again but still doesn’t seem to get bored with it.
2. verb (3rd singular form) – to look after someone or something for some time to make sure that the person or thing is safe,
She is such a good friend of mine – every time I need to stay at work longer, she watches my kids.
3. noun (plural form) – small clocks, usually worn on a wrist,
He’s got five different watches and he’s still going to buy another one – it’s simply a waste of money.

Collocations with watches:
A few common collocations with watches are: digital watches, watches in silence, and sits and watches.
Our store has a wide selection of digital watches so for sure you will choose something that suits you.
I hate when our teacher walks around the classroom and watches in silence how we work.
I temporarily share the office with my boss, which is so stressful as I have the impression that he only sits there and watches me.

Incorrect spelling, explanation: while spelling the word watches, many users of English forget about the rule, which says that we need to add the -es ending to this word – no matter if it is a noun or a verb. As a result, a common spelling mistake is to write watches as watchs, which is incorrect.