'A year' can be any year without any specification. But 'the year' means a particular/specified year or the one which is already mentioned and thereby known. E.g: In a year there are twelve months.

Understanding the Context

(means any year or all years) I was born in the year 2000. (in that particular year) Grammatically 'a/an' is known as indefinite article and 'the' is definite article. The indefinite article (a/an ... The New Year or New Year - English Language & Usage Stack Exchange I am writing about some leadership stuff, and I am trying to say that I am leading the 14-15 year old boys.

Key Insights

How do I correctly use year-olds as in, "I was the adviser to the 14-15 year-olds." Than... BENGALURU β€” Long-dated U.S. Treasury yields will hold steady in the near term but rise later this year on inflation and Federal Reserve independence concerns, while short-dated yields edge down on ... CNBC on MSN: 10-year Treasury yield hovers near 4.3% after oil price gain, sticky inflation data The 10-year Treasury yield was little changed on Thursday as oil prices rallied and investors digested a number of key data releases. 10-year Treasury yield hovers near 4.3% after oil price gain, sticky inflation data The comparison with "the second year and the last year" supports plural rather than singular.

Final Thoughts

In that "full" version, each occurrence of the word year clearly relates to a single year. Unless you're talking about Chinese (or Persian) New Year, the name of the celebration isn't New Year but New Year's Eve, and it happens on the last day of the old year. I'd say 'across the year' hints strongly at sporadic events etc, whereas 'throughout the year' speaks more of consistent results. But this is opinion, and I doubt I'll easily find supporting evidence I can use to justify an 'answer'. You can check individual examples to see if my suggested rule-of-thumb seems to apply. As (I think) Lambie says, 'across my lifetime / several years' are probably ...