${2.}$ We aren't old enough to go on holiday alone.

${3.}$ This bed isn't soft enough.

${4.}$ This film is too boring.

${5.}$ It is too cold to go to the beach.

${6.}$ Her family weren't rich enough to go on holiday.

⇒ S + Vbe (not) + too + Adj + (for +O) + to_V

= S + Vbe (not) + Adj + enough + (for+O) + to_V

2. we're not old enough to go on holiday alone

3. this bed is not soft enough

4. this film is too boring

5. it is too cold to go to the beach

6. his family were not rich enough to go on holiday

=> Dạng phủ định với động từ tobe

S + be not + adj + enough + (for SB) + to V.