It is friends that/ who offer to give us a hand when we are in trouble,and it is also they that encourage and confort us when we are upset and depressed.两句中都用了强调句型和when状语从句.
或者
Not only do friends offer to help us when we are in trouble,but also they comfort and encourage us when we feel upset and depressed.
not only和but also连接两个句子,第一句要部分倒装.也都用了when状语从句哦.