Resh is common.It is not grammatical. If it is part of the word, it is part of the root. While it occurs frequently in Ruth, it is the first letter of only a few words, Ruth, famine, see, empty, wash, Ram. Curious, eh?
(that is still all feminine singular - should the adjectives agree with the subject of the verb (you singular feminine)? Empty appears to be indeclinable. Hungry can take a feminine ending e.g. Psalm 107:9, נֶפֶשׁ רְעֵבָה).
We begin with Ruth 1:1
And we have empty twice, once in Ruth 1:21 and once in Ruth 3:17
But resh is also in the blessing of Ruth 2:4, the origin of our liturgical greetings - how well can you read this without translation? After many grammar and reading lessons, I can do it. My hit rate for a random scriptural passage is about 50% after 3 years. I mean, about half the words I will have to look up - and I still need to stop and read and think. There is no auto-recognition yet.