Tense Guide (English Abstract)

The body of a Chinese degree thesis is written in Chinese, which has no tense, so this guide and its script check apply only to the English abstract (Abstract). The English abstract should follow English-paper tense conventions. The goal is not to use past tense everywhere; each part has its own convention. The most common error is writing the method/results narrative in present tense.

The script (deai_check.py) runs only in the English abstract region: generic \begin{abstract}, thuthesis \begin{abstract*}, and pkuthss \begin{eabstract}. It skips Chinese abstract environments (explicit thuthesis \begin{abstract} and pkuthss \begin{cabstract}) and emits a [Script] LOW trace for present-tense reporting verbs there. If it cannot locate an English abstract, it performs no check.

Tense in the English Abstract

Part	Default Tense	Example
Background	Present	“Long-context inference is expensive ...”
Methods	Past	“We trained ... / Models were evaluated on ...”
Results	Past	“The model achieved 92.3% / We observed ...”
Conclusion	Present	“These results provide a basis for ...”

Body chapters (introduction/methods/experiments/conclusion) are written in Chinese and follow Chinese writing conventions, outside the tense script's scope. If the degree thesis requires English chapters, apply English-paper tense conventions: methods/results strictly in past tense, figure/table descriptions in present tense.

Signal Words (Scan Method/Result Sentences in the English Abstract)

The most common error is using a present-tense reporting verb where past tense is required:

• shows / reveals / demonstrates / indicates / presents / confirms / achieves / outperforms in a method/result narrative -> normally change to showed / revealed / demonstrated / …. The script flags these forms.

is / are - Manual Judgment (Not Flagged by the Script)

Present-tense is / are in English-abstract methods/results is often a tense error, but too many legitimate uses exist for automatic flagging. Retain present tense in these cases:

• Definition: “Let G be ... / The loss is defined as ...”;
• General fact: “Cross-entropy is convex ...”;
• Description of a figure/table: “Table 2 is organized by ...”;
• Software capability: “The toolkit supports ...”.

Otherwise prefer past tense: “The threshold was set to 0.5” rather than is set.

Exceptions Skipped by the Script (Present Tense Is Correct)

1. Figure/table/equation as subject: “Figure 3 shows ...”, “as shown in Fig. 4”, “Table 1 lists ...”.
2. Software/tool capability: “The library provides ...”.
3. A definition or general fact embedded in a methods paragraph.

Treat matches in these cases as false positives and retain the wording.

Boundary with Other Guides

• This guide covers tense. For claim strength (causal/first/universal), see over-claim-guard.md.
• For Chinese academic style, see academic-style-zh.md.

Script Support

deai_check.py (ChineseAITraceChecker) emits [Script] LOW traces for present-tense reporting verbs only in the English abstract region (configured in references/deai/tone-thresholds.yaml under the tense: section, controlled by enabled). The script filters figure/table and software false positives but does not judge is / are; apply the checklist above manually.