甚至 vs 甚至于

甚至 (shènzhì) and 甚至于 (shènzhìyú) both mean "even" or "so much so that", but they have subtle differences in usage, formality, and grammatical structure.

1. 甚至 (shènzhì) – "Even" (More Common & Flexible)

Usage:

• Used to introduce an extreme or unexpected example to emphasize a point.
• Can be used alone or with 都/也 (dōu/yě) for stronger emphasis.
• More flexible in sentence structure.

Examples:

1. 他工作很忙，甚至忘了吃饭。
   (He was so busy with work that he even forgot to eat.)
2. 这个字很难，连老师甚至都不认识。
   (This character is so difficult that even the teacher doesn’t recognize it.)
3. 他太累了，甚至站着都能睡着。
   (He was so tired that he could even fall asleep standing up.)

Key Features:

✔ More common in spoken & written Chinese
✔ Can appear before or after the subject
✔ Often used with 都/也 (dōu/yě)

2. 甚至于 (shènzhìyú) – "Even to the Extent That" (More Formal & Literary)

Usage:

• Used to introduce an extreme or exaggerated consequence.
• More formal, written, and literary (less common in spoken Chinese).
• Often implies "to such an extent that..."

Examples:

1. 他太紧张了，甚至于说不出话来。
   (He was so nervous that he couldn’t even speak.)
2. 这个决定影响很大，甚至于改变了整个行业。
   (This decision had such a big impact that it even changed the entire industry.)
3. 他沉迷游戏，甚至于不去上学。
   (He was so addicted to gaming that he even skipped school.)

Key Features:

✔ More formal & literary (common in essays, reports, speeches)
✔ Often implies a stronger consequence
✔ Less flexible in position (usually before the verb phrase)

3. Key Differences Summary

4. When to Use Which?

• Use 甚至 (shènzhì) for general emphasis (spoken & written).
• Use 甚至于 (shènzhìyú) for formal writing or extreme consequences.

Example Comparison:

✅ 甚至 → 他太懒了，甚至不想起床。 (He’s so lazy that he doesn’t even want to get up.)
✅ 甚至于 → 他太懒了，甚至于不想起床。 (He’s so lazy that he doesn’t even want to get up.)
(Here, 甚至于 sounds slightly more formal/literary.)

Final Tip:

• If unsure, 甚至 (shènzhì) is safer in most cases.
• 甚至于 (shènzhìyú) is best for formal writing or strong exaggeration.