Theory:

 
Alliteration is the occurrence of the same sound, if not a letter, at the starting of two or more words in a single line, in a poem.
1. The slender smiling girl.
2. The song of sweet birds.
3. Black bug bit a bear.
4. Practise the piano.
5. Feel the phone on your face.
What are the uses of alliteration?
 
1. It creates a rhythm, similar to rhyming words.
2. It emphasizes the importance of phrases.
3. Mostly used in tongue-twisters.
Alliteration used in the poem "No Men Are Foreign":
Remember, no men are strange, no countries foreign
Beneath all uniforms, a single body breathes
Like ours: the land our brothers walk upon
Is earth like this, in which we all shall lie.

They, too, aware of sun and air and water,
Are fed by peaceful harvests, by war’s long winter starv’d.
Their hands are ours, and in their lines we read
A labour not different from our own.

Remember they have eyes like ours that wake
Or sleep, and strength that can be won
By love. In every land is common life
That all can recognise and understand.

Let us remember, whenever we are told
To hate our brothers, it is ourselves
That we shall dispossess, betray, condemn.
Remember, we who take arms against each other

It is the human earth that we defile.
Our hells of fire and dust outrage the innocence
Of air that is everywhere our own,
Remember, no men are foreign, and no countries strange.