1. It is permissible to count in any language, provided that one understands that language. But if one does not understand that language – even if he said it in Hebrew – he does not fulfill his obligation; since he has no notion of what he has said, he not really “counted” anything (Mishnah Berurah489:5).
2. Some have the custom to say “Today is such-and-such to the Omer [לָעוֹמֶר],” while others say “in the Omer [בָּעוֹמֶר].” Either way, it is only the ideal way of phrasing the counting -to clarify that one is counting from the day of the offering of the Omer and on. But, after the fact, even if one only said, “Today is such-and-such days,” and he did not mention theOmerat all, he does fulfill his obligation (ibid.).
3. The Sephardic custom is to say the word לָעוֹמֶר, “to the Omer,” between the number of days and the number of weeks. For example, “Today is twelve days to the Omer, which are one week and five days.” This is also the custom of those who follow the teachings of the Arizal (Kaf HaChaim489:34).
