Learn Italian: Mangiamo sull'erba. - We eat on the grass.

In Italian, the preposition su (on) must merge with the definite article (the) that follows it. When su combines with l', it doubles the L and becomes the articulated preposition sull'.

Why do we use l' for erba instead of la?

Erba (grass) is a feminine noun. Normally, its article would be la, but because erba starts with a vowel, la drops its A and becomes l' so the words flow together smoothly.

Where is the word for "we" in this sentence?

Italian often drops subject pronouns like noi (we). The verb ending does the work for you: the -iamo ending on mangiamo tells us exactly who is doing the eating, making the pronoun unnecessary.

Do I pause when speaking at the apostrophe in sull'erba?

No, you shouldn't pause. The apostrophe is there to connect the sounds smoothly. You pronounce sull'erba continuously, as if it were a single.