1. do you have a handkerchief 2. do you have an handkerchief which sentence is correct plz explain

Do you have a handkerchief? - correct sentence. Sencond sentence is wrong because "handkerchief" word starts from consonant sound not a vowel sound so "a" used before "handkerchief" not "an".

When the first letter of any word is consonant, we use "a". Ex :- a ball. When the first letter of any word is vowel (a, e, i, o, u), we use "an". Ex :- an orange. Here, the first letter of the word "handkerchief" is consonant, we use "a" . So, "a handkerchief" is correct.

first sentence is correct because handkerchief not start from vowels

First one is correct

Do you have a handkerchief

we have a everything but is nothing I have

The 1st sentence is correct.