连 … 都 / 也 (even)

If a child can, anyone can

• to link连lián … all / both都dōu / also也yě … = "even …".
• to link连liánchild小孩xiǎo háiall / both都dōuto understand懂dǒng = "even a child understands."
• to link连lián throws a spotlight on a surprising, extreme case.

to link连lián + X + all / both都dōu / also也yě + Predicate

• to link连lián…all / both都dōu… says "even X (let alone the rest)".

even连liánchild小孩xiǎo háieven都dōuunderstand懂dǒng。

• to link连liánchild小孩xiǎo háiall / both都dōuto understand懂dǒng = "even a child gets it."

Implies the rest follow

• If even X is true, the easier cases certainly are.

Recap

Read the full reference: HSK 4 grammar — Basic sentence patterns.