英语中的省略句可以通过使用标志词如"That", "To", "For", "As", "If"等来增强理解。这些词可以分别用于引出宾语和表语从句、表示不定式符号、表示目的或原因、表示原因或方式以及表示条件。使用这些标志词可以帮助读者或听者更好地理解句子的意思，同时也需要注意语境的清晰和上下文的连贯。
下面是一些常见的省略句的标志词：
1. That
That 可以表示引出宾语从句和表语从句的引导词。例如：
- I believe (that) she is telling the truth.
- It's a pity (that) he couldn't come to the party.
2. To
To 可以表示不定式符号，表示动词不定式。例如：
- I want (to) go home.
- He needs (to) study hard.
3. For
For 可以表示介词，表示目的或原因。例如：
- He bought a car (for) transportation.
- She is studying hard (for) the exam.
4. As
As 可以表示连词，表示原因或方式。例如：
- As I was walking down the street, I saw a cat.
- He did his homework (as) his mother told him.
5. If
If 可以表示连词，表示条件。例如：
- If you come, I'll be happy.
- I will go to the party (if) I finish my work.
