Using different infinitive forms for the "unreal past" and "future"

Question

I assume these three sentences below have the same meaning. Only the first one conveys the message that the action of sitting happens for a longer period. Am I right?

• I'd like to have been sitting there when she walked in.
• I'd like to be sitting there when she walked in.
• I'd like to be there, sitting when she walked in.

These sentences are refereeing to the unreal past. My second question is that weather it would be alright to just change

when she walked in >

to

when she walks in

and keep the rest of the sentences unchanged, to talk about a wish?

Answer 1

Only to have been is correct in the first part of your sentence when used with when she walked in. We need to use have been because we are referring to an event in the past; saying I'd like to be expresses a wish about the present or future.

If you change when she walked in to when she walks in, you change the meaning of the sentence, from the past to the present tense. The present tense can refer to a general truth (like she walks in every day) or a planned future event (like she walks in at 8 o'clock tonight). If you use she walks in, then you have to wish to be (sitting) there to match.