Learn Italian: Confondo sempre tutte e due le sorelle perché sono identiche. - I always confuse both sisters because they are identical.

When using tutti e due (or its feminine form tutte e due) with a noun, you must always include the definite article. It translates literally as "all and two the sisters". This same rule applies to the other word for "both", entrambi.

Could I use "entrambe" instead of "tutte e due" in this sentence?

Yes, you could say entrambe le sorelle. Both expressions mean "both" and they are completely interchangeable in everyday conversation. Just remember that both of them require the definite article (le) before the noun.

I noticed "sempre" comes after the verb. Can I say "sempre confondo" like in English "I always confuse"?

No, that is a common trap for English speakers! In Italian, adverbs of frequency like sempre (always) usually go immediately after the conjugated verb. Saying sempre confondo sounds unnatural.

Why does the word "identiche" have an "h" in it?

The singular feminine adjective is identica. When making it plural, the ending changes to -e. To keep the hard "c" sound (like a "k") before the "e", Italian adds an "h". Without the "h", it would be pronounced with a soft "ch" sound.