～が ほしい

I wish I had a new pair of shoes!

a. あたらしい くつが かいたい なあ。
b. あたらしい くつが すきだ なあ。
c. あたらしい くつが ほしい なあ。
d. あたらしい くつ たい なあ。

The best answer is c. あたらしい くつが ほしい なあ。

～が ほしい means “I want ～” and it is usually only used in a first person sentence (i.e. when the sentence starts with わたしは, expressed or implied. You don’t use ほしい when somebody else wants something.) Also, as is in English, “want” is a rather direct expression, so I try not to use it too often and when I use it I soften it by adding a postpositional particle like this なあ.

Let’s have a look at each option.

a. あたらしい くつが かいたい なあ。
= I wish I could buy a new pair of shoes.
This is probably the second best choice, but I may like to have new shoes given to me, rather than buying them myself, so ほしいなあ is the best answer. The ending なあ in this sentence suggests it is a wish.

b. あたらしい くつが すきだ なあ。
= I like  new pairs of shoes, I should say!
あたらしい くつが すきだ is a simple statement and here なあ ending gives an exclamatory effect.

d. あたらしい くつ たい なあ。 – This is a grammatically incorrect sentence.