Grammar books vary vastly in guidance on Modal verbs and the Conditional or Unreal Past. We can exercise our grammar relativity, to manage.
10.4. MORE WORKOUT FOR REAL-TIME TALK

Verbal pattern to regard the character of activity or faculty, as Simple or Indeterminate, Progressive or Continuous, Perfect, and Perfect Progressive or Continuous. Grammar guidance is not uniform on Aspect names.
Grammar books vary vastly in guidance on Modal verbs and the Conditional or Unreal Past. We can exercise our grammar relativity, to manage.
We can use Form Relativity with the Progressive and real verbs. We can use stories. “I’d be reading horoscopes”, says Ms. Seges. “That is …?” (Mr. Seges does not believe Ms. Seges would ever read horoscopes.) “This looks like a calligraphic copy of Vespucci’s letters. It was slipping out of our backyard hedge, no covers or front matter.” “Hadn’t it sure taken a lot to make such a book, I’d suspect that Babbitt next door. Bill once wrote me the book I was looking for was as likely to be obtained as a calligraphic of Vespucci’s originals. It was completely a legend, he checked with the Freeman’s.”
We do not have to view Modal, Conditional, or Unreal Past patterns as separate. With Perfect tenses, our syntactic HAVE helps tell about real time. It has an open real-time frame. With the Unreal Past or Conditional, HAVE tells about hypothetical time. HAVE is not part the real map, then. It comes with an auxiliary compass for relative time.
We can view verb forms as generally relative, for hypotheses. PRESENT forms can tell about the FUTURE. PAST forms can tell about the PRESENT. ANTECEDENT PAST forms can tell about the PAST.
Our use of the word "relativity" is not about physics or families. It is linguistic. We can acquire the Modal relativity step-by-step, and spare our arrows. Let us remember they indicate the target time, not the verb form.
Modal Expression, especially the Interrogative or Negative, can give us some trouble, unless we approach the matter as science in a field: we analyze the molecules, see how they are doing, and make a model. We can recur to CHAPTER 5, as well as compare APPENDIX 4. 54. We CANNOT skip the exercises. … Continue reading 9.3. DETAIL ON MODAL STRUCTURES
We can actually live only in the real-time PRESENT. Our syntactic HAVE does not bring assertion about real time, when we attach it to a Modal and make a hypothesis. We do not need to view it as open-frame real time, then. We can view it as a syntactic anchor and a closed-frame hypothetical time.
Let us focus on the auxiliary have. Would it make antecedent time extents altogether? Antecedent time extents always would be relative to the head time. To shape up a good idea for head verbs and time, we can venture common sense, as also in literature. The common sense truth here is that it can take real time to make hypotheses, but hypothetical time could never be the same as real time.
. . . Let us think about Madame Règle. She has the potential to have lunch at Latimer Sauf’s restaurant every day. He always has a table for his friends and she has enough money. However, her work with Paris haute couture designers often keeps her over the lunchtime. Her coming to lunch is probable, but not certain. CERTAINTY requires both potentiality and probability. Let us think about Monsieur Sauf’s birthday. Madame Règle will come to meet him. It is certain.
To practice independent language use, we have only part the cues to put our verbs into the PAST, and then in the PRESENT. We mind Expression and do not give up on a mild sense of humor. “The grain of sand could think about wisdom. What was wisdom? It might be a grain of wit and manhood well resolved, but the grain of sand did not consider going into a drama like that of Samson the Agonist really necessary. Thinking about own format as potentiality by another, it deliberated whether it was, as a grain of sand, a fruit of ability or mere industriousness.”