Answer:
Sentence with correct grammar is;
Please bring me an egg timer.
Step-by-step explanation:
The first sentence is correct as it correctly use an indefinite article "an" before a word which starts with vowel sound (egg).
The second sentence is incorrect because it incorrectly uses an indefinite article ("a") before a word which starts with a vowel sound (honor).
It is important to remember that the selection of one of the indefinite articles ("a" and "an") is determined by the sound with which a word starts. If it is vowel sound the article "an" is used; and if it is a word which starts with constant sound article "a" is used.
Examples:
an historical event, a house, an hour, an honor, an umbrella, a unit, a yellow car, a European company.
Some words may have different starting sounds depending on the accent used (e.g American, British, Indian etc.).