Have we got a lot to learn about the fifth letter? Probably, and I won't go too deep for a first foray. 'He' is first 'the' letter. It has its own word in the interjection הא (The first few do also: Aleph is itself a thousand, bet is almost a house, gml is payback, getting what you deserve, dalet - poor, weak - with a little help from a taf.)
The first use presented of ה in the grammar books is that of the definite article. Right at the beginning of Ruth, it appears in this construct phrase:
In Ruth 1:11 we find the second major use of ה, the interrogative
In chapter 2, besides many definitives and interrogatives, I see this strange spelling of earth -
Most of the rest of the uses of ה in Ruth are definite, or feminine markers, or interrogative. BDB lists 13 subdivisions of the definite. I won't list them all - maybe in a deeper, later post, though one (the vocative BDB I.i. p 208) came up in discussion of Psalm 117 here. In Ruth we have at least one instance of 'tonight' (I.c. p207) = 'the night' הַלַּיְלָה and here is another that may fit somewhere:
A little tidbit on the bottom of page 222 in Lambdin notes how the hiphil of halek looks as if it were the hiphil of yelek. I already encountered this confusion of two verbs that are treated as one in the Hebrew concordance that I have. See note on Ruth 1:15-18.
And Happy New Year to you all.