The only infixes in the English language are obscenities!
An infix is an affix inserted inside a word stem (an existing word). It contrasts with adfix, a rare term for an affix attached to the end of a stem, such as a prefix or suffix.
Also, the word Infix means to fix in the mind or to instil. An example of a sentence with the word infix is: Infix a picture into the text. Synonyms to the word Infix include insert, introduce, and enter.
An infix is a word element which can be placed within the base form of a word. This is to come up with a new word or an exaggerate meaning. English has almost no factual infixes.
The only infixes in the English language are obscenities like fuckin', as in "Un-fuckin'-believable". Other languages, such as Spanish, do have a lot of infixes.