How to explain the use of the -te form in "takasugite kaemasen"?


In the exercise section of the chapter on potentials in my textbook, the
answer to the question "kimono wo, kaimashita ka?" is given as "iie,
takasugite kaemasen deshita." Unfortunately, in neither the discussion
covering -te forms or potentials is the reasoning explained. Does the
potential in this case necessitate the usage of "takasugite"? Also, does it
forbid the use of "kara", as in "takasugite kara kaemasen deshita"




高い｛たかい｝(takai) is 'to be expensive'. To say something is **too** expensive, or
**too much** of any i-adjective, we remove the final i and add すぎる (sugiru).
This makes a new verb 高すぎる｛たかすぎる｝(takasugiru) which means 'to be **too**
expensive).

Now we can manipulate this new verb just like any other verb. In particular we
can change it in to the て-form to give 高すぎて｛たかすぎて}(takasugite). In its
simplest interpretation て just acts like 'and', so the full sentence becomes

> No, it was too expensive **and** I couldn't buy it.

But this 'and' implies causality just like it would in English so it is
equivalent to using 'because'.

Your final suggestion "takasugite kara kaemasen deshita" doesn't make sense
because "verb-te kara" mean " **after** doing verb" so in this case "after too
expensive". You could say "takasugiru kara ..." to mean "because it is too
expensive". This would have an equivalent meaning.

