The phrase "be into one for" can have different spellings depending on how it's pronounced. In IPA phonetic transcription, it's written as /bi ˈɪntu wʌn fɔr/. Some possible spellings are "be into 1 4," "be in2 1 4," or "be intu wan for." The phrase means that someone has developed an interest or enthusiasm for something, often something unusual or unexpected. It can be used in a variety of contexts, such as "I never thought I'd be into gardening, but lately, it's become one of my passions."