あの人はこの大学の学長に相違ない。
- That person must be the president of this university.

あの人はこの大学の学長に相違ない。 meaning: That person must be the president of this university.

The sentence follows a typical Japanese sentence structure, Subject-Topic-Object-Verb, although the subject can sometimes be implied. ⚫︎ あの人 ("That person") functions as the topic, marked by the topic marker は. ⚫︎ この大学の学長 ("the president of this university") functions as the object of the preposition, using the possessive particle の to connect "this university" この大学 and "president" 学長. ⚫︎ に is a particle indicating the target or direction of the action or state. ⚫︎ 相違ない ("must be") is a fixed expression indicating certainty or strong belief. It acts as the verb in this sentence.

相違ない is a formal and literary expression meaning "it must be," "there is no doubt," or "certainly." It indicates a high degree of certainty based on the speaker's observation or reasoning. ⚫︎ It always comes at the end of a sentence. ⚫︎ It is often used with the particle に. ⚫︎ It's an N1-level expression and is considered relatively formal. ⚫︎ It is used to express certainty, almost like a strong conclusion. It's similar in meaning to はずだ but is considered more formal and definite. ⚫︎ Example: 彼が犯人であることに相違ない - "There is no doubt that he is the culprit."

The particle に has multiple uses. In this sentence, it functions to indicate the target or the state that is being asserted. ⚫︎ に can also indicate the location of an action (e.g., 学校に行く - "to go to school"). However, the usage here is different. ⚫︎ In this context, it indicates the state of being the "president." The person is "being in the state of" the president. ⚫︎ This usage is common before adjectives that describe the object, the subject is in an actual state of an objective. ⚫︎ Example: この問題は重要だ - "This problem is important"

This construction indicates possession or a relationship between two nouns. It's a fundamental part of Japanese grammar. ⚫︎ In the example sentence, この大学の学長 describes "the president *of* this university." ⚫︎ の connects the two nouns, showing that the second noun (president) belongs to or is associated with the first noun (this university). ⚫︎ This structure is extremely common in Japanese and is essential for forming complex noun phrases. ⚫︎ This is a very common N1-level structure and is used very frequently. ⚫︎ Example: 日本の文化 - "Japanese culture."

は marks the topic of the sentence. The topic is what the sentence is about. ⚫︎ は is often translated as "as for..." or "speaking of..." but it doesn't always have a direct English equivalent. ⚫︎ In the example, あの人は means "As for that person..." or "That person,..." ⚫︎ The topic is usually the thing the speaker already knows about or has introduced. ⚫︎ は can also replace other particles. ⚫︎ Example: 私は学生です - "As for me, I am a student" or "I am a student".