Case suffixes generally help to recognize the roles of words in a sentence. Although some word endings might relate to different cases or to verb forms, many endings are rather sure signs of a specific case being used.
For example, we can analyze the structure of the sentence Liprakoissa hulmingoissa häimylöi nuhkuisia jupsuja without knowing any of the words. From the endings we can infer that the first two words are in inessive plural and apparently form an adverbial, consisting of an adjective and a noun. The last two words appear to be in partitive plural, presumably an adjective and a noun, constituting the subject of the sentence. This makes it rather obvious that the third word is a predicate, as it most probably is according its form: if a word ends with a diphthong, like öi, it is a past tense form of a verb (with few exceptions). Therefore we can expect the last two words to constitute the object, consisting of a noun and its attribute in partitive plural (due to the endings -ia and -ja). So we know the grammatical structure, with no idea of the meaning. Actually, there is no meaning; the words were just invented for this example.
However, there are more complicated situations. Due to the variation in meanings of cases, a sentence may contain two phrases in the same case, for unrelated reasons. This is not forbidden, though it may make a sentence more difficult to understand.
In particular, the genitive often appears in different meanings in a sentence, due to its many uses. The same applies to the partitive. This means that we may need to analyze a sentence or part of a sentence first in one way, then deduce that the analysis must be wrong, and take a different path.
For example, the start of the sentence Kannatamme työttömyyttä vähentäviä toimia can first be read as meaning “We support unemployment”, but both the meaning and the continuation of the sentence make this interpretation impossible. Although the partitive työttömyyttä could grammatically be the object of kannatamme, this interpretation would make it impossible to make the rest of the sentence fit into the grammatical structure. Leaving työttömyyttä aside for a while, we get a meaningful analysis for the rest: vähentäviä toimia (reducing measures, i.e. measures that reduce) is in the partitive and constitute the object. We can then see that työttömyyttä is indeed an object, but for the verb participle vähentäviä. So the meaning is “We support measures that reduce unemployment”. The Finnish sentence is not optimal for understandability, and Kannatamme toimia, jotka vähentävät työttömyyttä might be better. However, administrative, political, scientific, and many other texts often contain sentences loaded with phrases in the same case.