The verb shake refers to making something tremble . Trembling, meanwhile, refers to shaking , moving with jerks that can be caused by different causes.
Returning to the idea of shuddering, it can be a physical effect generated by a roar or an impact . For example: “The beginning of the concert made the windows of my house shake,” “The earthquake once again shook the structure of the city's buildings, although this time no significant damage was reported,” “According to the environmental organization, the “Nuclear tests are going to shake the islands in the area with an unpredictable result.”
The most frequent use of shudder, however, is linked to a startle or an excitement of the mood . Shivering may be the consequence of a fright or another emotion that appears suddenly or intensely.
It is important to keep in mind that the action of shaking, in these cases, is usually symbolic. This means that it does not always include a tremor that is registered in the body: “The singer managed to shake the public by performing an emotional version of her most popular song,” “The announcement of the Mexican club managed to shake social networks and soon became in trend” , “The filmmaker, this time, could not shake the critics, who agreed to rate his new proposal negatively” .
Suppose a man is resting on a beach when he suddenly notices that he has an iguana on his shoulder. This unexpected presence makes him shudder, experiencing fear and a certain repulsion generated by contact with the animal.
Before continuing, we must make a clarification regarding the conjugation of this verb. In the first meanings that we have mentioned in this definition, its function is that of a transitive verb : this means that it requires a direct object to complete its meaning. In most of the previous examples we can find this characteristic: shaking " the glasses " , " the islands " , " the social networks " .
To check that it is a direct object, all you need to do is replace it with la, lo, las or los , as appropriate to its gender and number, and see if it maintains the meaning: «shake the « (the glass) and « shake the « (the islands and social networks). As we can see, although the detail of "what shook" is lost, by offering the interlocutor the appropriate context , it is correct to rewrite the previous sentences in this way.
However, in the example of the man who is surprised by the iguana, we do not use the verb with its transitive function but rather a pronominal one . Pronominal verbs are those that require an unstressed personal pronoun for their conjugation, more precisely those that belong to the reflexive series: me, te, nos, os and se . This must agree in gender, number and person with the subject of the sentence and, it is worth clarifying, it does not have a syntactic function .
Returning then to the verb shudder, in this case we notice that the man "shudders", and therefore the meaning can adopt one of the following two meanings: "shiver suddenly and agitated"; "feeling a start or a nervous jolt suddenly." Taking this into account, we could say that the following two statements are equally valid: "the iguana shook the man" , "the man shuddered in the presence of the iguana" .
Although so far we have mentioned some of the synonyms of the verb shudder, let's see below a concise list: shake, shake, tremble, vibrate , tremble, palpitate, chill, be disturbed, frightened, excited, upset, moved, horrified, startled , be terrified, scared and alarmed. Note that many of them are pronominal verbs, which tells us that they correspond to "shudder."