The meanings "say" and "tell" are very similar, but there are subtle differences in how they are used in English with reported speech. "Did you say that to her?" puts the emphasis on the words that you used. "Did you tell her that?" puts the emphasis on the content of what you said. "I said to her that she was fired." "I told her that she was fired." Although the both are reported speech, the implication in the first is that I used the word "fired." In the second, there is no indication that I used those words, only that I conveyed the information. "Tell" can also have an indirect object -- "I told her that" -- but "say" does not. You'd have to say, "I said that to her." There are also contexts where one is preferred: "Tell me a story," not "Say me a story" or "Say a story to me." When translating, "Abair" usually corresponds to say or speak and "inis" to tell or relate.