Therefore means for this reason, thus, or consequently. It is an adverb, often used as a conjunctive adverb or sentence connector. Rarely, therefore is used as a noun to mean an inference.
Therefor is an archaic form meaning for that object or purpose, in exchange for this or that or it. Mostly used formally or in legal documents, therefor is an adverb and is related to the adverbs thereof which means of that, thereafter which means after that, and therein which means in there. Use of the word therefor peaked in about 1915, and has steadily dropped until it is now employed almost entirely in formal or legal documents.
Also, see our article on using therefore in a sentence.
“Therefore we have decided to accelerate our cost reduction and efficiency measures — which I know will have tough consequences for employees across the group.” (Houston Business Journal)
Since we have a firm belief in our moral correctness, therefore when a conspiracy theory can not “absolve” an act of terrorism , our natural response is to label it as merely a reaction to the “atrocities” committed by the West. (Huffington Post)
Those more likely to stay in work are also wealthier, with better-paid jobs and larger super balances, and are therefore more likely to invest in income streams over consumption. (Australian Financial Review)
Additionally, the rules state: “In circumstances that are flagrant and particularly injurious to the success of a tournament, or are singularly egregious, a single violation … shall also constitute the major offence of ”aggravated behaviour“ and shall be subject to the additional penalties hereinafter set forth therefor.” (The Independent)
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