No me imagino lo que está pensando.

English Translation

I can’t imagine what he is thinking.

I had expected esté (subjunctive), as there is uncertainty involved.

Edit: or maybe future tense: lo que estará pensando?

2 Likes

Saying “I can’t imagine what he is thinking” is the same use of “imagine” as “I imagine he’s coming to the party”, as a fanciful way of saying you know or don’t know something (like suponer). This is very different from imagining unrealistic/fantastical events such as no puedo imaginar que sea una ballena nostálgica.

2 Likes