思う vs 考える, 知る vs 分かる — Thinking Verbs Fully Explained

English gets by with "I think" for almost everything, but Japanese forces you to choose between 思う and 考える — and picking the wrong one can make you sound either too casual or overthinking. The same split exists for "know" (知る vs 分かる). Let's sort these out once and for all.

思う vs 考える: Gut Feeling vs Logical Thinking

This is the pair that trips up learners from beginner to intermediate:

明日は雨だと思う。 → I think it'll rain tomorrow. (gut feeling)

この問題をじっくり考える。 → I'm going to think this problem through carefully. (deliberate analysis)

彼は優しいと思います。 → I think he's kind. (subjective impression)

将来のことを考えなければならない。 → I need to think about the future. (requires planning)

The Core Rule

• A fleeting impression or opinion → 思う
• Something that takes time and logic → 考える
• "I think A is B" (expressing an opinion) → 思う
• "Let me think about it" (needs processing time) → 考える

Key Grammar Patterns

日本に行こうと思います。 → I'm thinking of going to Japan. (expressing intention — only 思う works here)

この問題について考えましょう。 → Let's think about this problem. (analyzing together — only 考える works here)

知る vs 分かる: Knowing vs Understanding

Another pair that causes endless confusion:

彼の名前を知っていますか。 → Do you know his name? (do you have this information?)

この漢字の意味が分かりますか。 → Do you understand the meaning of this kanji? (do you truly grasp it?)

Critical Grammar Difference

In daily conversation, 知る almost always appears as 知っている (state of knowing) or 知らない (not knowing):

The negative forms have a subtle but important difference:

• 知りません → I don't have that information (never heard of it)
• 分かりません → I don't understand (aware of it, but can't grasp it)

A: 田中さんの電話番号を知っていますか。 → Do you know Tanaka's phone number?

B: いいえ、知りません。 → No, I don't. (I don't have that information)

A: この文法が分かりますか。 → Do you understand this grammar point?

B: いいえ、分かりません。 → No, I don't. (I've seen it but can't make sense of it)

信じる vs 信頼する: Believing vs Trusting

彼の話を信じる。 → I believe what he said. (believing the content is true)

彼を信頼している。 → I trust him. (trust in the person, built over time)

サンタクロースを信じていますか。 → Do you believe in Santa Claus? (believe in the existence of something)

In short: 信じる is about content/facts, 信頼する is about people/relationships.

覚える vs 思い出す vs 忘れる: The Memory Trio

These three verbs describe different stages of memory:

新しい単語を覚えました。 → I memorized the new vocabulary. (input stage)

急に昔のことを思い出した。 → I suddenly recalled something from the past. (retrieval stage)

パスワードを忘れました。 → I forgot my password. (loss stage)

An interesting nuance: 覚えていない (don't remember) and 忘れた (forgot) are close in meaning but different in tone:

• 覚えていない → It's not in my memory (maybe I never stored it)
• 忘れた → I used to know it but have since lost it

迷う vs 悩む: Being Torn vs Being Troubled

赤にするか青にするか迷っている。 → I can't decide between red and blue. (choice paralysis)

人間関係で悩んでいる。 → I'm troubled by my relationships. (emotional distress)

道に迷った。 → I got lost. (literal sense of losing your way)

Quick test: 迷う is "A or B?" indecision; 悩む is "this is painful" distress.

Summary

• 思う (intuitive opinion) vs 考える (logical analysis) — express opinions with 思う, analyze with 考える
• 知る (possess information) vs 分かる (understand content) — 知っている/知らない are the standard forms
• 信じる (believe something is true) vs 信頼する (trust someone) — facts vs people
• 覚える (store in memory) → 思い出す (retrieve from memory) → 忘れる (lose from memory)
• 迷う (torn between choices) vs 悩む (troubled/suffering) — indecision vs distress

Practice Quiz

Q1. Fill in the blanks: 「来年、留学＿＿＿と＿＿います」 (I'm planning to study abroad next year).

Q2. A friend asks if you know that new ramen shop. You've never heard of it. How do you respond in Japanese?

Q3. 「AとBのどちらにするか＿＿っている」 (I'm torn between A and B) — fill in 迷 or 悩?