'AS IF' and 'AS THOUGH'

You can use as if or as though at the beginning of a clause when you are describing how someone or something looks, or how someone behaves.

It's a wonderful item and in such good condition that it looks as though it was bought yesterday.

He lunged towards me as if he expected me to aim a gun at him.

Many people think it is incorrect to use 'was' in clauses of this type. They say you should use were instead.

He looked at me as if I were mad.

She remembered it all as if it were yesterday.

However, in conversation people usually use was.

The secretary spoke as though it was some kind of password.

He gave his orders as if this was only another training exercise.

You can use was or were in conversation, but in formal writing you should use were.

Some people say like instead of 'as if' or 'as though'.

He looked like he felt sorry for me.

Shaerl put up balloons all over the house like it was a six-year-old's party.

This use is generally regarded as incorrect.

Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012