Canis sub lecto iacet, et infans eum tangere vult.

Because sub can take two different cases:

• ablative for location: under the bed
• accusative for motion toward a place: to under the bed / under the bed in the sense of movement

Here the dog is already there, lying still, so Latin uses the ablative: sub lecto.

Compare:

• Canis sub lecto iacet = the dog is lying under the bed
• Canis sub lectum currit = the dog runs under the bed

So lecto is ablative singular.

Canis is nominative singular, so it is the subject of iacet.

A few clues help:

• iacet is a singular verb, so it needs a singular subject.
• canis is the dictionary form of the noun: canis, canis
• if it were the direct object, you would normally expect canem, not canis

So canis is the one doing the action: the dog is lying there.

Iacet comes from iaceo, iacere and means lies or is lying.

It is more specific than just is. Latin often uses verbs that describe posture or position:

• iacet = lies, is lying
• sedet = sits, is sitting
• stat = stands, is standing

So canis sub lecto iacet does not just mean the dog exists under the bed; it means the dog is lying there.

Eum is the accusative masculine singular form of is, ea, id, and here it means him or it.

It refers back to canis and serves as the direct object of tangere:

• infans = the child
• eum tangere vult = wants to touch him/it

Latin uses eum because the dog is being treated as masculine here. If the dog were feminine, Latin would use eam.

Because English and Latin do not always handle animals the same way.

In Latin, a noun can have grammatical gender, and pronouns must agree with it. So a masculine dog can be referred to as eum.

In English, we often refer to an animal as it, especially when its sex is not important. But if we think of the animal personally, we may also say him or her.

So eum is grammatically masculine in Latin, but English may naturally translate it as either him or it, depending on context.

Because after vult Latin normally uses an infinitive.

• vult = wants
• tangere = to touch

So:

• eum tangere vult = he/she wants to touch him/it

This is very similar to English. The main difference is that Latin does not need a separate word like English to in front of another verb; the infinitive ending already shows that idea.

Infans is a third-declension noun: infans, infantis.

In this sentence it is:

• nominative singular
• the subject of vult

So infans is the one who wants to touch the dog.

It can refer to a very young child and can be masculine or feminine depending on the child, even though the form infans itself stays the same in the nominative singular.

Because Latin word order is much more flexible than English word order.

English relies heavily on position:

• the child wants to touch him

Latin relies more on endings, so several orders are possible:

• eum tangere vult
• vult eum tangere
• tangere eum vult

All of these can mean basically the same thing. The endings show what each word is doing. In this sentence, putting vult at the end is very natural Latin.

Latin does not have articles like English the and a/an.

So:

• canis can mean the dog or a dog
• infans can mean the child or a child
• lecto can mean the bed or a bed

The context tells you which English article makes the most sense.

Because lectus is a second-declension noun, and its ablative singular ends in -o.

So:

• lectus = nominative singular
• lecto = ablative singular

Since sub here requires the ablative, lectus changes to lecto.

So the phrase is built like this:

• sub
  • lecto
• under
  • the bed