To make your meaning plainer; make your first statement clear.
When we didn't understand Fritz, he went on to explain himself.
To give a good reason for something you did or failed to do which seems wrong.
When Jack brought Mary home at three o'clock in the morning, her father asked him to explain himself.
To say what you think or feel; put your thoughts or feelings into words by speaking or writing.
The boy expressed himself well in debate.
The mayor expressed himself as opposed to any borrowing.
fall over backwards
fall over oneself
fall over yourself
fall over someone
To do everything you can to please someone; try very hard to satisfy someone.
Делать все чтобы порадовать кого-нибудь; пытаться изо всех сил удовлетворить чьи-либо желания.
The hotel manager fell over backwards to give the movie star everything she wanted.
The boys fell over themselves trying to get the new girl's attention.
My aunt falls all over me whenever she comes to visit.
Моя тетя с меня пылинки сдувает, когда приходит в гости.
To find out what one is fitted for and succeed in that.
Mary tried several lines of work, but at last found herself as a teacher.
Sometimes young people move around a long time from job to job before they find themselves.
To be sure of your own talent or skill; highly confident.
I flatter myself that I am a better swimmer than he is.
fling yourself into something
Тратить все свое время и энергия на что-то.
Ever since she flung herself into the anti-pollution campaign, she rarely has a free moment!
С тех пор как она со рвением принялась за кампанию по защите окружающей среды, у нее нет свободной минуты.
To do something one should have remembered not to do; do something below one's usual conduct although one knows better; let one's self-control slip.
He forgot himself only once at dinner - when he belched.
He knew he should hold his temper, but because of the trouble he forgot himself and began to shout.
full of oneself
Interested only in yourself.
Joe would be a nice boy if he would stop being so full of himself.