Why do JLPT N2 learners confuse ～難い with ～沿い?

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 ～難い or ～沿い more common on JLPT N2?

Both appear in the JLPT N2 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 Counters & Affixes theme of N2 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 N2 · Upper Intermediate · Meaning confusion

～難い vs ～沿い

Q: What's the difference between ～難い and ～沿い?

～難い (～がたい) means "hard (difficult) to do ~" and ～沿い (～そい) means "along". Both are suffixes that modify verb stems. Confusion arises from their structural similarity as suffixes, but ～難い (difficult) expresses psychological difficulty, while ～沿い (along) describes a physical path along a landmark.

Why JLPT N2 learners mix up ～難い (～がたい, “hard (difficult) to do ~”) and ～沿い (～そい, “along”).

～難い

～がたい

hard (difficult) to do ~

i-adjective

～沿い

～そい

along

i-adjective

Theme: Counters & AffixesJLPT N2

Why these get confused

Both are suffixes that modify verb stems. Confusion arises from their structural similarity as suffixes, but ～難い (difficult) expresses psychological difficulty, while ～沿い (along) describes a physical path along a landmark.

How to tell them apart

Anchor on the meaning, not the form. ～難い (hard (difficult) to do ~) and ～沿い (along) 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

～難い (hard (difficult) to do ~)

信じ難いな。
これは許し難いな。

～沿い (along)

川沿いを歩いたよ。
彼は海岸沿いに歩いた。

How JLPT tests this pair

On JLPT N2, 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

「～難い」の意味は？