Why do JLPT N1 learners confuse 乃至 with お目出度う?

Both words occupy adjacent semantic territory, which is exactly why the JLPT uses them as distractors for each other on multiple-choice items. The fastest way to stop confusing them is to study them as a pair, write a one-sentence contrast in your own words, and drill the pair specifically rather than each word in isolation.

Is 乃至 or お目出度う more common on JLPT N1?

Both appear in the JLPT N1 curriculum and either may show up on a given exam. Don't try to predict which one the test will choose — learn to distinguish them and you'll be safe regardless. Both belong to the General Expressions (1) theme of N1 vocabulary.

How do I practice this confusion pair?

Free option: visit /try and pick a confusion drill. Paid option: none — JLPT Mastery is free during launch. Whichever route you take, the engine specifically re-tests pairs you've gotten wrong rather than rotating through general vocabulary review.

JLPT N1 · Advanced · Meaning confusion

乃至 vs お目出度う

Q: What's the difference between 乃至 and お目出度う?

乃至 (ないし) means "from...to, between...and, or" and お目出度う (おめでとう) means "(ateji) (int) (uk) Congratulations!; an auspicious occasion!". Both are formal, high-register expressions. 乃至 (from...to) is a technical conjunction for ranges, while お目出度う (congratulations) is a standard polite greeting; learners may confuse them when reading formal documents.

Why JLPT N1 learners mix up 乃至 (ないし, “from...to, between...and, or”) and お目出度う (おめでとう, “(ateji) (int) (uk) Congratulations!; an auspicious occasion!”).

乃至

ないし

from...to, between...and, or

expression

お目出度う

おめでとう

(ateji) (int) (uk) Congratulations!; an auspicious occasion!

expression

Theme: General Expressions (1)JLPT N1

Why these get confused

Both are formal, high-register expressions. 乃至 (from...to) is a technical conjunction for ranges, while お目出度う (congratulations) is a standard polite greeting; learners may confuse them when reading formal documents.

How to tell them apart

Anchor on the meaning, not the form. 乃至 (from...to, between...and, or) and お目出度う ((ateji) (int) (uk) Congratulations!; an auspicious occasion!) live in adjacent semantic territory. Memorize the boundary, not just each word.
Read the example sentences below. Seeing each word in its natural context builds a faster lookup than studying the dictionary form alone.

In a sentence

乃至 (from...to, between...and, or)

私、かわいくないし。
お前のこと、うらやましくないし。

お目出度う ((ateji) (int) (uk) Congratulations!; an auspicious occasion!)

おめでとう！
優勝おめでとう。

How JLPT tests this pair

On JLPT N1, this pair shows up as a vocabulary meaning question. You see one word and pick its English equivalent from four options — one of which will be the other word in this pair, chosen as a distractor precisely because of the overlap.

Sample item

「乃至」の意味は？