Question

I need to buy some new clothes for the summer.

to buy some new clothes to buy is asking what new clothes. I am saying an adverb again

Answer 1

1. What is the WHOLE infinitive phrase?

2. Re-think what this phrase is doing. Re-read the five examples of infinitive phrases I already gave you. Also study this: "Adverbs can be single words, or they can be phrases or clauses. Adverbs answer one of these four questions: How? When? Where? and Why?"
http://www.chompchomp.com/terms/adverb.htm

Let me know what you decide.

Answer 2

to buy some new clothes

to buy what some new clothes A noun

Answer 3

Whole infinitive phrase:
to buy some new clothes for the summer

The main clause is "I need" -- and the infinitive phrase is serving as a noun, the direct object of "need." See the second example here:
http://grammar.ccc.commnet.edu/grammar/phrases.htm#infinitive

Answer 4

write down the details in the seating of "how much land does a man need ?"