Con (With) and Su (On)

This page covers two of Italian's nine simple prepositions: con (with) and su (on, about, around). Both are A1-level, both are extremely frequent in everyday speech, and both have small but important quirks worth covering together: con has two surviving article-contractions (col, coi) plus a family of archaic ones; su is fully regular in its contractions but introduces the special su di rule before disjunctive pronouns. Once you have these two prepositions in hand, plus the five we've covered elsewhere (di, a, da, in, per), you have the high-frequency core of the Italian system.

The two prepositions don't compete for the same semantic territory — con covers accompaniment, instrument, and manner; su covers surfaces, topics, and approximation — so they coexist easily. We treat them in one page because both are A1 and both have distinctive contraction behavior.

Part 1: Con (with)

1. The four core uses of con

Con covers four major semantic territories:

These are the daily uses that cover almost all of con's frequency. Let's take them in turn.

2. Accompaniment: doing something with someone

The first use of con is being together with another person — accompaniment.

After con, pronouns take their tonic (disjunctive) forms — never the subject pronouns:

A note on archaic forms: poetic and 19th-century Italian uses meco (with me), teco (with you), and seco (with himself / herself) as merged single-word forms — vieni meco (come with me). These survive only in literature and in fixed expressions; in modern Italian, always use con me, con te, con sé. Encountering meco in Petrarch or Foscolo is normal; producing it yourself would sound like a parody.

3. Instrument: doing something using a tool

Con also marks the instrument or tool used to perform an action.

The contrast with a for means is small but real. A marks bodily means (a piedi — on foot, a mano — by hand, a memoria — by heart). Con marks a separate tool or implement (con la penna, con il coltello, con la chiave). The crossing case is a mano vs. con la mano — a mano means "manually, by hand" (an abstract method: fatto a mano = handmade), while con la mano means "with the hand" as a specific physical action (ho preso la palla con la mano = I caught the ball with my hand).

4. Manner: how something is done

Con + abstract noun expresses the manner in which an action is performed — the equivalent of an English adverb in -ly.

This pattern is enormously productive — almost any abstract noun can take con to form a manner phrase. The result is often more natural than the corresponding adverb in -mente. Con calma is more common than calmamente; con cura is more common than curatamente.

5. Composition: ingredients and combinations

A useful smaller use: con marks what is included or combined with something — typically food and drink.

The contrast with al / alla + ingredient is subtle: pasta al pomodoro and pasta con il pomodoro are both common. Al is slightly more idiomatic in fixed dish-name contexts (spaghetti al pomodoro, pollo al limone); con is more general and emphasizes the addition.

6. Contractions: col and coi (and the archaic rest)

Con is unusual in Italian: it has two surviving article-contractions in modern speech — col (con + il) and coi (con + i) — plus a family of archaic ones that you'll encounter in older texts but should not produce.

Modern usage:

Col is especially frequent in fixed expressions that have crystallized with the contracted form: col tempo (over time, with time), col passare degli anni (with the passing of years), col cuore in mano (with one's hand on one's heart, sincerely), col senno di poi (with hindsight). In these contexts, con il would sound stilted.

The other historical contractions — collo, coll', colla, cogli, colle — are firmly archaic. You'll encounter colla (con + la) in 19th-century literature ("Andò colla madre" = he went with his mother), but modern Italian writes con la madre. The same applies for the rest.

7. Quick reference for con

The full picture in one table:

Part 2: Su (on, about)

8. The four core uses of su

Su is less frequent than con (about 5% of preposition tokens vs. 8%), but its core meanings are very productive:

9. Surface: position on top of

The basic, concrete meaning of su is position on top of a surface. This is the closest English-Italian 1:1 mapping in the location system: English "on" → Italian su.

The pattern with su is consistent: it marks a stationary position on top of a surface, with the article required (and contracted).

10. The contractions: sul, sullo, sull', sulla, sui, sugli, sulle

Su is fully regular in its contractions with the definite article — all seven forms are obligatory:

These contractions are mandatory in every register. Su il tavolo and su la sedia are ungrammatical — the contraction must happen.

11. Topic: about, on a subject

A productive use of su: it marks the topic of a book, lecture, article, conference, study, etc.

The contrast with di for topic is real and worth noting:

• Parlare di (to talk about) — di is the standard preposition for general conversational topics: parliamo di calcio, parliamo di te.
• Un libro su / una conferenza su — su is the standard preposition for topical works (books, lectures, articles, studies): un libro su Dante, una conferenza su Galileo.

The rough rule: di for conversation about something; su for a piece of work whose subject is something. Parlare di Dante (to talk about Dante, in conversation); un libro su Dante (a book about Dante, as a topic of study).

12. The crucial su di + pronoun rule

This is a quirk of su that surprises many learners. Before disjunctive pronouns, su requires the insertion of di — never bare su me or su lui.

This is the same rule that applies to other compound prepositions ending in adverbs: sopra di me, sotto di te, dentro di noi, dietro di lui. The di insertion is mandatory before disjunctive pronouns; it does not appear before nouns (su Marco — about Marco; su di lui — about him).

The same pattern is mirrored in con: while you can say con me without inserting di, the parallel preposition contare su (to count on) always uses su di before pronouns. This is a quirk worth memorizing — the construction contare su qualcuno (to count on someone) becomes contare su di me, di te, di lui.

13. Approximation: around, about (with numbers and ages)

A specialized use of su: it marks approximate quantities, times, or ages.

The pattern uses su + i/le + number, with the article required and contracted. The contracted form follows the gender of the implicit unit: sui trent'anni (with i — fixed in this idiomatic approximation, even though anni normally takes gli), sulle quattro (su + le ore — implicit hours, plural feminine).

The expression su per giù is fixed and universal — it's the conversational way to say "roughly, give or take, more or less." Native speakers reach for it constantly.

14. Motion onto: getting on top of something

Su with verbs of motion marks moving onto a surface or vehicle:

The verb salire ("to climb, to get on") is paired with su as its standard preposition: salire sul treno, sulla montagna, sull'aereo. Note that for trains and other vehicles, both salire sul treno (more common) and salire in treno (less common, slightly old-fashioned) are heard.

15. Quick reference for su

Part 3: How they differ

16. Con vs. su — a clean separation

The two prepositions don't compete for the same semantic territory. The rough mapping:

The only crossover point is the "on the table for meals" idiom: a tavola (at the table, for meals) uses a, not su. Su is for the physical surface of a table; a tavola is for the social context of eating. Il libro è sul tavolo (the book is on the table — surface); siamo a tavola (we're at the table — eating).

17. In vs. su — interior vs. surface

A finer-grained contrast: in marks interior, su marks surface.

This is one of those distinctions that English collapses but Italian preserves — useful when you want to specify whether something is inside a container or on top of a surface.

18. Common mistakes

The errors English speakers make most often with con and su.

19. The combined picture

Both prepositions in one summary table:

20. The mental model

Three reflexes for these two prepositions:

1. Con = with (people, tools, manner). Pronouns take tonic forms. Con me, con te, con la chiave, con calma.
2. Su = on (surface, topic, approximation). Contractions are obligatory. Sul tavolo, sui trent'anni, un libro su Dante.
3. Su + pronoun requires di: su di me, su di te, su di lui. This is the trickiest sub-rule on this page — memorize it as a unit.

Once these reflexes are in place, con and su become two of the most useful prepositions in your toolkit — covering everyday situations like going out with friends, cooking with ingredients, talking about books, and counting on people.

Where to go next

• Prepositions: Overview — the architectural map of all nine simple prepositions, including con and su in their high-frequency context.
• Tonic Pronouns: Overview — the me, te, lui, lei, noi, voi, loro forms that follow every preposition (with the su di-insertion rule).
• Tonic Pronoun + Con / Di Contraction — the detailed treatment of con me / con te and the di insertion rules for compound prepositions.
• Preposizioni Articolate — the full contraction grid, including the sul, sullo, sulla, sui, sugli, sulle paradigm.
• The Preposition In: Overview — the partner of su in the location system: in for interiors, su for surfaces.