Infinitival relative clauses
We can make a special type of defining (read 'restrictive') relative clause in English using an infinitival clause. As with other relative clauses the infinitival clause comes after the noun it modifies. If we want to include the subject of the relative clause, we need to use for at the beginning of the clause:
- They are the team [to beat].
- They are the team [for us to beat].
In the first sentence we need to understand the Subject of the verb beat from the context. We probably understand it as people. In the second sentence the speaker has told us who the Subject is .
These types of relative clause usually have modal meanings to do with obligation of ability. They often mean something similar to should or can. We can understand the sentence above as:
- They are the team [who we should beat].
Notice that just like other relative clauses these relative clauses have an antecedent. In our examples, the antecedent for the infinitival relative clauses is the word team. And like other relative clauses, these relative clauses also have a gap in them. We can model those sentences like this:
- They are the team [(for people) to beat ____ ].
- They are the team [for us to beat ____].
We use the antecedents to interpret the meaning of those gaps we understand the sentences like this:
- They are the team [for us to beat
or like this:
- They are the team(i) [ for us to beat ____(i) ]
If the antecedent (strictly speaking, the gap) is the Subject of the relative clause, we cannot use for. We only use for when we use an overt Subject. If we don't us an actual phrase to say who the subject is, we don't use for. Here is an example:
- She is the woman [
the woman to lead us to victory]
Here we understand that the Subject of the relative clause is the woman. We have to have a gap in the clause where the subject is. We cannot use for:
- She is the woman to lead us to victory.
- *She is the woman for to lead us to victory. (ungrammatical)
In this example, we understand that the relative clause means something like who can lead us to victory.
Infinitival relative clauses with non-modal meanings
In special circumstances, we can use infinitival relative clauses with non-modal meanings. These are the special circumstances:
The larger noun phrase must have a special modifier. It can be either a superlative like largest, youngest, most interesting, a special word like only, next, last, latest, or an ordinal number, for example first, second, hundredth.
- Maria was the oldest runner to compete in the marathon.
- Bob will be the only elephant to compete in the marathon.
- Sherpa Tenzing Norgay was the first person to climb mount Everest.
The antecedent must be interpreted as the Subject of the infinitival relative clause. All of these relative clauses have gaps as Subjects. From this we understand that in the first example above it was Maria who competed in the marathon. It was Bob who finished the race. The understood subject of to climb is Sherpa Tenzing Norgay.
Notice that because there is no overt Subject in the clause, just a gap, we cannot use for here.
Infinitival clauses have no tense. In these situations we understand the time reference of the infinitival clause from the context. We understand from the first, Maria, example that she was the oldest runner who competed in the marathon. WE understand from the elephant example, that Bob will be the first elephant who will compete in the marathon. We understand this from the verbs in the matrix clause.
Remember that to negate an infinitival clause we usually put not before the word to. Here are some examples:
- You're the first person not to laugh at that joke.
- It was the only tree not to be blown over.
Advice on teaching infinitival relative clauses
For FCE (Upper intermediate or B2 on the CEFR) you probably most need to teach the non-modal relative clauses. I wouldn't normally introduce them as relative clauses at all.
Students need to recognise modifiers such as first, only, next and so forth. They need to understand how to use infinitival clause like defining relative clauses to show which first, only or next thing we are talking about:
They need to understand how to negate such clauses, in other words the best place to put not.
The rest should fall into place. The terminology is not important. Nobody will ever test them on it. Good luck!
Don't try to teach these as a reduced form of wh- relative clause. Most infinitival relative clauses will not allow a wh- word at all. We can only use them in very, very special circumstances which are very difficult to identify and explain. Very often there is no easy transformation from a finite wh- relative clause to an infinitival one. The biggest danger however is that your students may try to transform relative clauses which don't meet criteria (1) or (2) into infinitival relative clauses. It simpler and easier just for them to understand if you just demonstrate how to use infinitival clauses in the same way that we use normal relative clauses - to define what 'only' or 'first' thing we are talking about.