〜すぎる

Verb ます-stem / い-adjective (drop い) / な-adjective (drop な, keep the stem only) + すぎる — e.g. 静か + すぎる = 静かすぎる, NOT 静かなすぎる.

• このかばんは高すぎて買えません。

  このかばんはたかすぎてかえません。

  This bag is too expensive, so I can't buy it.

• 食べすぎないでください。お腹を壊しますよ。

  たべすぎないでください。おなかをこわしますよ。

  Please don't eat too much. You'll upset your stomach.

• この問題は難しすぎませんか。

  このもんだいはむずかしすぎませんか。

  Isn't this problem too difficult?

• 昨日のパーティーは静かすぎた。

  きのうのパーティーはしずかすぎた。

  Yesterday's party was too quiet.

• そんなに心配しすぎないでね。

  そんなにしんぱいしすぎないでね。

  Please don't worry so much, okay?

• これ、辛すぎない？

  これ、からすぎない？

  Isn't this too spicy?

• 忙しすぎて、休む時間もなかった。

  いそがしすぎて、やすむじかんもなかった。

  I was too busy, so I didn't even have time to rest.

• Attaching すぎる to the full dictionary/ます-form instead of the correct stem (incorrect: 飲むすぎる, 飲みますすぎる; correct: 飲みすぎる).
• Forgetting to drop the final い of い-adjectives before すぎる (incorrect: 高いすぎる; correct: 高すぎる).
• Treating すぎる as simply meaning 'very' — it always carries the nuance of 'too much, more than desirable,' so praising someone with 元気すぎる or 優しすぎる can sound like a mild criticism or exaggeration rather than plain praise; for neutral 'very,' use とても instead.
• Keeping な on な-adjectives before すぎる (incorrect: 静かなすぎる; correct: 静かすぎる) — な-adjectives attach すぎる to the bare stem, with no な.

とても (very)

とても is a neutral intensifier meaning simply 'very,' with no implication that the degree is excessive or undesirable: とても高いです (It's very expensive — neutral observation). すぎる specifically implies the degree is excessive, beyond a desirable or acceptable amount, often with a negative consequence: 高すぎます (It's too expensive [to buy] — implies a problem).

あまり〜ない (not very / not much)

あまり〜ない describes something being not very / not much of a certain degree (understating a quality): あまり高くないです (It's not very expensive). すぎる is the opposite direction — describing an excessive degree, not an insufficient one: 高すぎます (It's too expensive) — these two patterns describe opposite ends of degree, not variants of the same idea.

N4 tests correct stem formation before すぎる for verbs, い-adjectives, and な-adjectives in fill-in-the-blank and word-ordering questions; reading/listening sections use すぎる to signal a negative consequence, so understanding what problem follows (often て + a negative result) is also tested.