Is it grammatically wrong using present perfect tense before only when when it is placed in the middle of the sentence as follows:
I have bought my books only when I have been accepted to the college.
Is it grammatically wrong using present perfect tense before only when when it is placed in the middle of the sentence as follows:
I have bought my books only when I have been accepted to the college.
It is grammatical, but it does not mean the same thing as
I bought my books only when I was accepted to college.
We can use after or once instead of when to say the same thing.
Your example means
Every time I have applied to college, I bought my books only after I was accepted.
One reason we use the present perfect is to communicate that we have done something repeatedly, and that is what it suggests in your sentence.
This is grammatical, but it may not mean what you intend.
The "present" in your sentence is understood as the present of habitual practice—"Throughout my academic career I have bought my books only when I have been accepted to college."
But your when clause appears to refer to a single past event, and you cannot modify a present perfect with a time expresssion which does not include the present. You have to use a simple past, bought, in your main clause, and a past perfect to relate the prior acceptane to that past purchase:
I bought my books only when I had been accepted to college.
Before trying to answer your question, let’s analyze your statement.
I have bought my books only when I have been accepted to the college.
Main clause (independent): I have bought my books
Subordinate clause (dependent): only when I have been accepted to the college
The idea is to discuss verb tense sequence, of which the starting point would be the main clause in this Complex Sentence. The main clause is Present Perfect, and the rule for this tense in the main is that the subordinate, for any purpose, is expressed in the Past Tense: (changes are needed)
CORRECT: I have bought my books only when the college accepted me.
Present Perfect Tense: have bought + Past Tense: accepted
The changes, of course were needed to make the dependent clause strictly Past Tense.
Moving the dependent clause, which is really an adverb dependent clause, does not change the meaning of the sentence:
Only when the college accepted me, have I bought my books.
It’s really a Mix ‘N’ Match deal with this type of structure which relies primarily on sequencing the verb tenses in clauses to be grammatically correct between them.
This would be for the main clause in the Past Tense:
I bought my books only when the college accepts me. [accepts = present tense used to state a general truth or show habitual action (you do this with any or all colleges that accept you)]
Or again, the Past Tense for the sub clause:
I bought my books only when the college accepted me.
Here’s the source: