Teenagers 11 Grammar practice

SOME LINKS TO PRACTICE: 

https://www.shertonenglish.com/es/gramatica/conectores/condicionales

https://www.englishgrammar.org/providing-long-exercise/

GAMES: https://www.eslgamesplus.com/nature/

Unless

Conditional clauses can begin with unless. Unless means something similar to ‘if … not’ or ‘except if’.

The verb forms in the examples are similar to sentences with if: we use the present simple in the unless-clause and shall, should, will, would, can, could, may or might in the main clause:

Unless I phone you, you can assume the train’s on time. (If I do not phone you /except if I phone you, you can assume the train is on time.)

We’ll have to cancel the show unless we sell more tickets at the last minute. (We’ll have to cancel the show if we do not sell more tickets/except if we sell more tickets at the last minute.)

Warning:

We don’t use unless for impossible conditions:

If the government had not raised food prices, there would not have been so many protests.

Not: Unless the government had raised food prices …

Warning:

We don’t use unless and if together:

We’ll go to the coast tomorrow unless it rains.

Not: We’ll go to the coast tomorrow unless if it rains.

BY THE TIME:

used for saying what has already happened at the time that something else happens

By the time we arrived, the other guests were already there. 

Until is a preposition and a conjunction. Until is often shortened to till or ’til. Till and ’til are more informal and we don’t usually use them in formal writing.

 

Until as a preposition

Until as a preposition means ‘up to (the time that)’:

We played chess until midnight. (up to midnight)

The film didn’t end till eleven o’clock.

We use from with until or till to talk about when something begins and when it ends:

I worked out at the gym from 6 pm till 7.30 pm.

The road outside our house will be closed from 6 am until 6 pm tomorrow.

We use by, not until, to talk about something that will happen before a particular time or deadline:

The movie will be finished by 9 pm.

Warning:

We can’t use until or till to mean ‘in advance of’. In this case we use before:

Please return your registration form before you leave the room.

Not: Please return your registration form until you leave the room.