* Since- এর পরবর্তী clause-টি present indefinite present perfect tense clause-টি indefinite form হয়।
Structure: Present indefinite/ Present perfect + since + Past indefinite.
Examples:
Two years (pass) since he went there.”
Ans. Two years have passed since he went there.
Since-এর পূর্ববর্তী clause-টি past indefinite tense এর হলে এবং since যদি সময় (time) নির্দেশ করে তাহলে এর পরবর্তী clause-টির past perfect tense হবে।
Examples:
It was many years since I (see) you.
Ans. It was many years since I had seen you.
কিন্তু since যদি কারণ (cause) নির্দেশ করে, সেক্ষেত্রে since-এর পরবর্তী clause-টিও past indefinite হবে।
Examples:
1. I ate all the chocolates since you (leave) them behind. Ans. I ate all the chocolates since you left them behind.
2. Since he was poor, he never (take) taxis.
Ans. Since he was poor, he never took taxis.
Before এর পূর্ববর্তী clause-টি past perfect tense হলে পরবর্তী clause-টি past indefinite tense হয়।
Structure: Past perfect + before + past indefinite.
Examples:
We had reached the station before the train (to start).
Ans. We had reached the station before the train started.
* After-এর পূর্ববর্তী clause-টি past indefinite tense এর হলে পরবর্তী clause-টি past perfect tense হয়।
Structure: Past indefinite + after + past perfect. Examples:
We reached the station after the train (start).
Ans. We reached the station after the train had started.
* As if/ As though এর পূর্ববর্তী clause-টি present indefinite tense-এর হলে পরবর্তী clause-টির past indefinite tense হয়।
Structure: Present indefinite + as if/ as though + Past indefinite.
Examples:
He talks as if he (be) a millionaire.
Ans. He talks as if he were a millionaire.
* As if/As thuogh এর পূর্ববর্তী clause-টি past indefinite tense-এর হলে পরবর্তী clause-টির past perfect tense হয়।
Structure: Past indefinite + as if/ as though + past perfect.
Examples:
He talked as though he (not know) it.
Ans. He talked as though he had not known it,
* When, after, before, that, until, since, as, because, as soon as, as though, than, ইত্যাদি দ্বারা যুক্ত বাক্যের Principal clause-টি Present বা Future indefinite tense-এর হলে Sub-ordinate clause টির Present perfect tense হয়।
Structure: Present/ Future indefinite + connecting word + present perfect.
Or, Connecting word + Present perfect + Present/ Future indefinite tense.
Examples:
1. I shall go to the station after the train (arrive).
Ans. I shall go to the station after the train has arrived.
ii. When you have worked hard you (be successful) successful in the examination.
Ans. When you have worked hard you will be successful in the examination.
* When, while, before, after, that, than, since, as, because, as though, as if, till, until, ইত্যাদি সময় (time) নির্দেশক conjunction দ্বারা যুক্ত বাক্য এর একটি verb, Past indefinite tense এর হলে অন্যটি Past perfect tense-এ হবে।
Structure: i. Past indefinite + connecting word + past perfect.
Or, ii. Past perfect + connecting word + past indefinite.
Examples:
i. It was long since I (see) you last.
Ans. It was long since I had seen you last.
il. Meena (be) at the orphanage since she was five.
Ans. Meena had been at the orphanage since she was five.
iii. Everyone said that he (kill) the snake.
Ans. Everyone said that he had killed the snake.
iv. You arrived after he (leave).
Ans. You arrived after he had left.
V. The doctor (come) before the patient died.
Ans. The doctor had come before the patient died.
To বা Until দ্বারা যুক্ত বাক্যের একটি present, future বা imperative হলে অপরটির simple present tense হয়।
Structure: Future/ Present/ Imperative + till/ until+ present indefinite.
Example:
Wait till I (come) come back.