Today’s page has two sentences. The bare bones of the first are Marcellus ambulat Marcellus is walking. The Adverb interea meanwhile links this sentence with what has come before. The Prepositional Phrase ad zoopolium to the pet store tells us to where Marcellus is walking. Marcellus is described by the Present Active Participle tenens holding. The Object of tenens is epistolam letter. The Prepositional Phrase in manu in [his] hand tells us where Marcellus is holding it. quam in suo limine modo invenit is a Relative Clause. A Relative Clause tells us a little more about the word to which it relates, which in grammatical terms is called the Antecedent. A Relative Clause begins with a Relative Pronoun - here quam which - that has the same Gender and Number as its Antecedent. The Antecedent of quam is epistolam. The Verb in the Relative Clause is invenit he found. The Adverb modo just tells us when Marcellus found the letter. The Prepositional Phrase in limine on the threshold tells us where he found it. limine is described by the Reflexive Possessive Adjective suo his. (Reflexive simply means that it refers back to the Subject of the sentence, in this case Marcellus.)
Marcellus meanwhile is walking to the pet store holding in his hand the letter which he just found on his threshold.
The bare bones of the second sentence are anxior solito videtur he seems more anxious than usual. The Verb video videre to see has two potential meanings in the Passive Voice, to be seen or to seem. anxior more anxious is the Comparative Form of the Adjective anxius anxious. solito than usual is an Ablative of Comparison. While the Subject of videtur is not written, it can be understood as Marcellus from the Third Person Singular ending of the Verb. This Understood Subject is described by the Present Active Participle circumspectans looking around and the Perfect Passive Participle sollicitatus having been disturbed. omnibus by all the things is an Ablative of Cause (who makes these names up?) working with sollicitatus to tell us what Marcellus has been disturbed by. It may be worth mentioning that omnibus is an Adjective being used Substantively, which means it is playing the role of a Noun. quae modo legit is another Relative Clause. The Relative Pronoun is quae which and its Antecedent is omnibus. The Verb in the Relative Clause is legit read. The Adverb modo just tells us when Marcellus read these things.
He seems more anxious than usual, looking around, disturbed by all the things which he just read.