Correct spelling for the English word "letted it happen" is [lˈɛtɪd ɪt hˈapən], [lˈɛtɪd ɪt hˈapən], [l_ˈɛ_t_ɪ_d ɪ_t h_ˈa_p_ə_n] (IPA phonetic alphabet).
"Letted it happen" is a nonstandard phrase that does not exist in standard English. However, it appears to be a combination of two separate words, "let" and "happen," which have their own distinct meanings.
The word "let" is a verb that indicates permission or the act of allowing something to occur. It can also express the release of an object or the renting out of property. For example, "I let my sister borrow my car" or "The landlord lets tenants live in the apartment."
On the other hand, "happen" is a verb that refers to the occurrence or taking place of an event without apparent cause or intention. It suggests that something occurred by chance or spontaneously. For instance, "The accident happened suddenly" or "I cannot control what happens in the future."
Thus, when combining "let" and "happen" in the nonsensical construction "letted it happen," the phrase suggests an action of permitting or allowing an event to take place naturally or without interference. While native English speakers would not use this particular phrase, its intended meaning seems to align with the concept of allowing a situation to unfold or accepting the occurrence of an event without proactive intervention or prevention.