What does the "だった" in "だったっけ" mean?


From what I can find out, たっけ is just an expression that shows that you're
trying to remember something, but what does the だった part mean? I have a few
guesses, but they don't seem to match what I can understand from it.

> 今日一限から英語だったっけ




The particle **-kke** is an interrogatory particle that marks a recollection,
or the failure thereof, in the case a question word appears. The particle's
usage is often introspective: the speaker asks him/herself whether something
is recollected properly.  
Recollections are usually about the past, but it is possible to ask oneself
whether a certain event in the future, or a state that ranges from the past
into the present, is properly recalled. In that case, many languages use past
tense to mark the non-past event.  
The particle _-kke_ often appears with **-da** , or its past form **-dat-ta**
, as in the OP's example _eigo-dat-ta-kke_. In the form _-dat-ta-kke_ , past
tense **-dat-ta** emphasizes the function of introspective speech marked by
**-kke**. Translations into English can then use the past tense, and possibly
the adverb **again** :

> 何だったっけ  
>  nan-dat-ta-kke  
>  'What was (that) again?'

The OP's example must be understood in one specific way. The example is
repeated below:

> 今日（の）１限（目）から英語だったっけ？  
>  'Was it English from the first period today?'

Since the example contains 今日 **きょう** , rather than 今朝 **けさ** , we can infer
that the speaker asks **before** class. S/He is trying to recollect whether
English is the first subject of the day. In that case, the speaker tries to
recollect (remembered) data of a future event. Even though the event is about
the future, the past tense **-dat-ta** serves to emphasizes the introspective
function of **-kke**. The English translation shows that using the past tense
in these situations is not unique to Japanese.




The particle **-kke** is an interrogatory particle that marks a recollection,
or the failure thereof, in the case a question word appears. The particle's
usage is often introspective: the speaker asks him/herself whether something
is recollected properly.  
Recollections are usually about the past, but it is possible to ask oneself
whether a certain event in the future, or a state that ranges from the past
into the present, is properly recalled. In that case, many languages use past
tense to mark the non-past event.  
The particle _-kke_ often appears with **-da** , or its past form **-dat-ta**
, as in the OP's example _eigo-dat-ta-kke_. In the form _-dat-ta-kke_ , past
tense **-dat-ta** emphasizes the function of introspective speech marked by
**-kke**. Translations into English can then use the past tense, and possibly
the adverb **again** :

> 何だったっけ  
>  nan-dat-ta-kke  
>  'What was (that) again?'

The OP's example must be understood in one specific way. The example is
repeated below:

> 今日（の）１限（目）から英語だったっけ？  
>  'Was it English from the first period today?'

Since the example contains 今日 **きょう** , rather than 今朝 **けさ** , we can infer
that the speaker asks **before** class. S/He is trying to recollect whether
English is the first subject of the day. In that case, the speaker tries to
recollect (remembered) data of a future event. Even though the event is about
the future, the past tense **-dat-ta** serves to emphasizes the introspective
function of **-kke**. The English translation shows that using the past tense
in these situations is not unique to Japanese.

