Correct spelling, explanation: the word spotted is a past participle and a past simple form of the infinitive to spot. It is made of a basis and a suffix. There is a rule in the English language that when we have a single vowel before the last and stressed consonant in a word, we need to double that consonant. Although, many people forget that rule. That’s why the correct form is spotted and the incorrect one is spoted.

Definition of spotted:
verb (past participle, past simple):
1. To see or notice something or someone, especially briefly or unexpectedly.
I spotted my friend in the crowd at the concert.
2. To mark or stain something with spots or speckles.
I accidentally spilled coffee on my shirt and it spotted the fabric.
3. To identify or locate someone or something in a particular place or situation.
The police officer spotted the suspect in the alley and chased after him.
4. To offer or find a job or opportunity for someone.
The company spotted her talent and offered her a promotion.

Collocations with spotted:
Some most commonly used collocations include:
1. spotted owl – a type of owl that is endangered and found in North America
The spotted owl is a symbol of conservation efforts in the Pacific Northwest.
2. spotted fever – an infectious disease transmitted by ticks
Spotted fever can cause serious illness if left untreated.
3. spotted hyena – a carnivorous mammal found in Africa
The spotted hyena is known for its distinctive laugh-like vocalization.

Incorrect spelling, explanation: spoted is a spelling mistake, because it doesn’t consist of the double -t letter, which is necessary in this case. Spot is a regular verb, which means that its conjugation shouldn’t be problematic to anyone. You need to add the suffix -ed to the end of the root. Although, we have to remember one principle: when there is a single vowel before the last and stressed consonant in a word, this consonant must be doubled. That’s why spotted is correct and spoted is not.