Well, this is one error that shows itself every single day – so let’s get it clarified once and for all.
It’s: This has two words – “it” and “is”. If we think of this as two separate words, we will always use it correctly. We should use this only if the sentence would make sense with both “it’s” and “it is”.
Its: This is the possessive pronoun of “it” – we should use “its” to indicate that something belongs to “it”.
- It’s a beautiful day! (= It is a beautiful day!)
- The baby is blinking its eyes! (Here, the eyes belong to the baby.)
- Look at the flower – it’s amazing to see its colors! (Here, it is amazing to see the colors of the flower.)