Although the word "kasí" is a native Tagalog word for “because” and not slang, it is still not used in formal writing. The Tagalog word for this is "sapagká’t" or "sapagkát." Thus, the formal form of "Batà pa kasí" is "Sapagká’t batà pa" or "Sapagkát batà pa." This is sometimes shortened to "pagká’t" or "pagkát", so "Sapagká’t batà pa" is also written as "Pagká’t batà pa" or "Pagkát batà pa." In both formal and everyday writing and speech, "dahil sa" (the oblique form of "kasí"; thus, its exact translation is “because of”) is also synonymous to "sapagká’t" ("sapagkát"), so the substitute of "Sapagká’t batà pa" for "Batà pa kasí" is "Dahil sa batà pa." Most of the time in speech and writing (mostly every day and sometimes formal), "dahil sa" as the Tagalog of “because” is reduced to "dahil", so "Dahil sa batà pa" is spoken simply as "Dahil batà pa."